Get a Free Rock & Mineral Fun Book for Your Kids!

Free Rock & Mineral Fun Book

We have a new free 53-page Rock and Mineral Fun Book available for kids, classrooms and home school families and groups. Sign up for our newsletter through the blog (top right corner) or on our website. You will get an email with a link to download the book. Please note that our newsletter is a double opt-in so once you complete the second opt-in you will immediately receive the email with the download link.The Rock and Mineral Fun Book includes:

  • Puzzles,
  • Coloring Pages,
  • Experiments,
  • Rock and Mineral Identification Flow Charts,
  • Image Galleries,
  • Birthstone Details,
  • Viktor’s Ice, the prequel novella to the Crystal Cave Adventure series.

We hope you enjoy our new Rock & Mineral Fun Book. If you have questions about any of the information in the book or other Mini Me Geology products, please contact us.

A Rock Weathering Experiment You Can Do In Your Kitchen!

Every day, rocks are subjected to wind, rain, and other mechanical processes that cause them to break down into smaller pieces and different forms. This process of weathering is part of the rock cycle and causes sedimentary, igneous, and metamorphic rocks to break down into smaller sediments and soil-sized particles. You can learn about rock weathering right in your own kitchen! Try this fun experiment to learn more about the mechanical weathering of rocks and post your results in the comments below.

Supplies for the Rock Weathering Experiment:

  • Plastic Wrap
  • Clay
  • Water
  • Hand Magnifier
  • Notebook
  • Pen
  • Camera (optional)

Step 1: Moisten the clay with a small amount of water. You want the clay to absorb as much water as possible without being dripping wet. Add a small amount of water to the clay and knead it until the water is absorbed, repeating until the clay is saturated.

Step 2: Divide the clay into two equal pieces and roll it into a ball or form a square.

Step 3: Wrap each piece of clay in plastic wrap.

Step 4: Place one piece of clay into the freezer and leave the other piece on a table or counter. Let the clay stay in the freezer overnight.

Step 5: The next day, remove the clay from the freezer and unwrap both pieces. Place the two balls of clay side-by-side and observe your results. Do the clay pieces look different after one day and then over time? If so, how? Write about your findings in a notebook and take pictures of the results after each day to see how the clay rock changes.

Step 6: Wrap each clay piece back up and put the one piece back into the freezer and repeat for several days. Observe the clay pieces each day and see how the cracks change over time.

Exerpiment Observations:

The clay from the freezer should have some cracks. Examine the clay with a hand magnifier to get a closer look at the cracks. The cracks result from the freezing and expanding water just like a rock that has water freezing in holes or existing cracks in the rock. Over time, the freezing and expanding of rainwater will cause a small crack in a rock to become big and allow the rock to split. If the frozen clay does not crack after several days, repeat the experiment with more water in the clay.

You can find more great activities like these in our Rock Cycle Kit and Rock Detectives Kits!

The Geology of the Blue John Cavern, home of the Famous Blue John Fluorite

The Blue John Cavern is located in the Peak District in England near the town of Castleton, Derbyshire. This unique are is the home of the world-famous Blue John Fluorite. There are two caves in the area that have this unique fluorite – the Blue John Cavern and Treak Cliff Cavern.









Area Geology Near the Blue John Cavern

The area is formed of limestone strata that deposited in deep ocean waters millions of years ago. Layers of shale and some gritstone, a type of coarse sandstone common in this area, covered the limestone. A generalized diagram of the strata is shown here.

Blue John Cave Formation

Over time, the layers buckled from folding and faulting. The cavern itself formed when glacial meltwaters flowed through the area forming the valleys and seeping into cracks in the limestone strata and dissolving portions of the limestone. As the meltwaters dissolved the limestone, underground rivers formed which washed out corridors and large underground rooms which became the network of the Blue John Cavern.

Blue John Fluorite

Fluorite is a unique mineral that can be found in more colors than any other including blue, red, purple, yellow, green, or white. Fluorite has low to moderate hardness, a white streak, and a glassy luster. Fluorite often forms in hydrothermal (hot water) veins inside other rocks and is often found with other minerals like galena, calcite, quartz, and sphalerite. Interestingly, fluorite crystals will fluoresce under ultraviolet light.

The Blue John Fluorite is a banded white and purple variety of the mineral shown here.

Adventures at the Blue John Cavern

The Blue John Cavern area is the setting for much of the book, Blue John’s Cavern, a time-travel, adventure novel for kids age 8 to 14. Join Emma and Brody as they travel through the magical Crystal Cave in search of the rare Blue John Fluorite! Read the book blurb on our website.

Blue John’s Cavern, and the entire Crystal Cave Adventures book series is available on our website. The series is also available wherever books are sold. Use this link to find your favorite retailer!

Blue John’s Cavern, and each of the four Crystal Cave adventures novels has a companion Activity Book full of puzzles, story quizzes, online games, fun geology facts, behind-the-scenes book details and creative writing activities! You can find the activity book on our website and everywhere books are sold.

The Fascinating Bay of Fundy

The Bay of Fundy is a geologically fascinating location in North America. I visited the bay in summer 1990 with my college geology department from Furman University.

Where is the Bay of Fundy?

The Bay of Fundy is approximately 174 miles long and located along the eastern coast of North America in the provinces of New Brunswick and Nova Scotia in Canada and on the northern side of the Gulf of Maine. I visited the Bay of Fundy during a college field trip and found the formation of the area fascinating. The bay is along the Atlantic Ocean and is subject to intensly dramatic tidal changes.

Tidal Changes at the Bay of Fundy

The fascinating tidal changes at the Bay of Fundy are worth an in-person visit one day. The photo to the right shows an area of the Bay of Fundy at low tide. You can see people walking along the low area.

The 12.5-hour tide cycles show a dramatic increase and decrease in the water level of the Bay. During this phenomenal change, over one billion tons of water flow into and out of the Bay of Fundy.

The highest recorded change between low and high tide was 54.5 feet, documented at Burncoat Head in Nova Scotia. Typical tides changes in the Bay are generally up to 49 feet per cycle and are most pronounced near the Minas Basin in Nova Scotia, Canada. The photo above shows the same area of the Bay of Fundy approximately 12 hours later at high tide. The area where the people were walking at low tide is completely flooded.

Geology and Biology of the Bay of Fundy Area

The Bay of Fundy is home to many birds, fish, and marine animals such as whales, dolphins, porpoises, fish, seals, and seabirds. The geology of the area consists of sandstone, 200 million-year-old basalts that formed as statues and cliffs, zeolites, and semi-precious stones including amethyst, agate, calcite, copper, jasper, and coal. The rolling in and out of the tide reveals fossils from the ancient rock layers as erosion occurs from 350 million-year-old carboniferous rocks.   In one area of the Bay of Fundy, the Joggings Fossil Cliffs in Nova Scotia, you can see an almost complete fossil record of the Pennsylvanian Coal Age, approximately 299 to 318 million years ago. The site also shows fossils from ancient reptiles and some of the oldest dinosaurs in Canada.

Have you visited the Bay of Fundy? If so, share your thoughts on this amazing location.

4 Tips to Make Your Kids Love Science with My Rockin Collection Rock & Mineral Kits

Rock and mineral kits are a beloved childhood toy. From our youngest geologists who pick up random rocks on the playground to older kids who explore outcrops in the woods, geology fascinates kids of all ages (and lots of adults too). Parents can use rock and mineral kits to elevate science in their kids minds and to promote other skills such as logical thinking and deductive reasoning in older kids and classifying and sorting in younger children.

Tip #1: Make Identification a Game

The My Rockin’ Collection Rock & Mineral deluxe kits have identification cards or an identification brochure (mineral kit) that has all of the information that you need to identify each of your samples. The name of each sample is below the foam in each slot but you can make the identification a game by having your kids try to identify the samples using the identification information before they look under the foam.

Tip #2: Use Deductive Reasoning to Find the Rock or Mineral Name

The Dig Into Geology section on the Mini Me Geology website has identification flow charts that you can download for each of the My Rockin’ Collection kits. Like the identification cards/brochure, the flow chart will help your kids identify their samples but in a different way. The flow charts move from left to right across the page and allow kids to discover the name of their sample using a variety of observations and tests. The flow charts also have pictures of the rocks and minerals so that the children can check their answers. The activities involved in identifying the samples will help develop logical thinking and deductive reasoning skills.

Tip #3: Allow Younger Kids to Develop Sorting and Classifying Skills

Younger children can benefit from using the rocks and minerals in the kits by sorting the samples. The identification flow charts will help you direct the kids with sorting exercises. The flow charts group the samples according to colors and textures that make it easy for younger children to follow. You can also encourage kids to come up with their own sorting groups based on anything that they observe as being different or similar in each of the rock and mineral samples.

Tip #4: Develop Ideas for Science Fair Projects

Encourage kids to develop ideas for science projects by examining the similarities between the rocks and minerals. What questions do they have that a science project can answer? Why do some rocks float while some sink? Why do some rocks seem to soak up water while others do not? Kids have endless curiosity. Allow them to explore their world by making lists of questions that they could turn into a school science project.

Learn more about each of our My Rockin’ Collection Rock and Mineral Kits. We are certain to have a great kit that your kids will love.


Meet the Cave of the Crystals – Giant Selenite Crystal Cave in Mexico

The Cave of the Crystal or the Giant Crystal Cave is a fascinating selenite cave in Naica, Chihuahua, Mexico. The cave was discovered in 2000 by miners who were excavating a new tunnel in the Naica Mine at a depth of approximately 300 meters (980 feet) below the land surface. Earlier, in 1910, a smaller room named the Cave of Swords was discovered at a depth of 120 meters (390 feet), above the Cave of the Crystals. The Cave of Swords contains amazing one-meter long selenite crystals covering the walls.

How the Giant Crystal Cave was Discovered

Brothers Juan and Pedro Sanchez, miners drilling in the Naica Mine to excavate a new tunnel for the Industrias Peñoles mining company, discovered the Giant Crystal Cave in April 2000. They were drilling through the Naica fault at the time. The Naica Mine is well-known for rich deposits of silver, zinc, and lead.

Inside the Cave of the Crystals with Massive Selenite Gypsum

The giant cave is located in limestone rock and is shaped like a horseshoe. The floor of the cave is covered in selenite gypsum blocks. The large blades rise from the blocks and the cave floor at varying angles throughout the cave. The Cave of the Crystals has spectacular, giant selenite gypsum crystals that are over 12 meters (39 feet) in length and 4 meters (13 feet) in width and weigh over 55 tons! These gypsum crystals are among the largest in the world.

The cave itself is very difficult to explore. The natural air temperatures inside the cave reach 136F with 90 to 99 percent humidity making it impossible to visit until you have protective clothing and equipment. Studying the cave has been a difficult challenge for scientists given the high temperature and humidity. Researchers must wear special protective suits that keep the body cool and provide fresh air. Even with the cooling suits, scientists were only able to spend between 30 and 45 minutes in the cave during each visit.

Selenite Mineral Properties

Selenite is a form of the mineral gypsum, also called Satin Spar. Satin spar is a fibrous variety of the mineral which forms in long strands, which grouped, form “sticks.” The following are the properties of the selenite mineral.

  • Chemical Formula:  CaSO4 . 2H2O
  • Color:  Colorless or White
  • Crystal Shape:  Tabular. Also may form twins or rosettes.
  • Cleavage:  Perfect
  • Fracture:  Conchoidal to splintery
  • Hardness:  2 on Mohs Hardness Scale
  • Streak:  White
  • Luster:  Pearly to Glassy
  • Density: 2.308 g/cm3
  • Uses:  Paints, Tile, Drywall, Blackboard Chalk, Fertilizer, Plaster of Paris

How the Selenite Crystals Formed Inside the Giant Crystal Cave

Scientists believe that the selenite crystals in the Giant Crystal Cave took approximately 500,000 years to grow to their current size. The heat in the cave results from a pool of liquid magma located approximately two to three miles below the main room of the cave. The cave periodically floods with water rich in gypsum minerals. The heat from the magma allows the selenite crystals to form from the mineral-rich water. The crystals form very slowly over a long time, which is why the selenite sticks are so huge.

Add Selenite to Your Collection

Mini Me Geology carries beautiful samples of selenite sticks, natural gypsum, and gypsum roses. These are fantastic minerals to add to your collections and they make a great gift for rockhounds as well! If you have any questions about any of our gypsum samples, please let us know.

Happy 50th Birthday Earth Day!

Earth Day was born on April 22, 1970. Every year, on April 22nd, we celebrate the wonders of our Earth and all that it has to offer and everything that we can do to help preserve its beauty and resources.

The Rise of the Environmental Movement

Throughout much of history, the environment was not of great concern. In 1962, the book Silent Spring by Rachel Carson, a life-long scientist, shed light on the negative impact of toxic chemicals on our environment. Ms. Carson’s legacy is fascinating and I encourage you to visit her website to learn more about this pioneering woman in science.

Silent Spring was an overwhelming bestseller and gave rise to the environmental movement. The book promoted concern for the health of our world’s animals, plants, and ecosystems and illustrated the potential destruction from reckless pollution.

The First Earth Day

Senator Gaylord Nelson from Wisconsin founded the first Earth Day. He was inspired to promote the environmental movement after he saw the effects of a large oil spill in Santa Barbara in 1969. Building on the environmental awareness that was growing in the world, he used Earth Day as a platform to change the way that air and water pollution were addressed in the United States. Over 20 million people participated in Earth Day in their communities. The day, aimed at teaching others about how to care for the environment and raising general awareness, drew crowds of people from young to old all across the country.

Earth Day Over the Years

Since 1970, Earth Day has become a global event that is celebrated in over 193 countries. The Earth Day Network helps to plan activities throughout the world to continue to bring awareness to the importance of caring for our environment. You can learn more about the Earth Day Network and how to become involved on their website.

Careers in Environmental Science

As a geologist, I spent many years working in the environmental industry as a consultant to corporations and individuals. My work involved assessing properties that had possible pollution then designing and executing a method for clean-up. Whether the site has soil or groundwater contamination, I and the companies I worked with, ensured that our clients were able to achieve their goals of protecting the environment.

If you are interested in working in the environmental arena, geologists and biologists are always in demand. You can work as a consultant, for the government helping to ensure that pollution is properly handled, as a researcher studying the environment and ways to keep it healthy, and much more. The Cool Jobs in Geology article may help you on your path as a future scientist. As always, if you have a question about careers in geology or environmental, contact me and I will be happy to help you find the right path forward.

Happy Earth Day!

What Mineral is My Birthstone and what are its Properties?

What's My Birthstone?

Crystals and gemstones have been associated with months of the year for almost 2,000 years. Today, we call them birthstones. Each birthstone is a unique mineral or mineraloid that has distinct characteristics.  What is your birthstone?

Garnet – January’s Birthstone

January’s birthstone is Garnet. Garnets are often found in metamorphic rocks such as schist. Garnets are actually a family of minerals which are all similar. The garnets which are often used as gemstones are typically a dark red color; however, the brilliant green of variety of uvarovite is rare and very prized.

Amethyst – February’s Birthstone

Amethyst is a common, purple form of the mineral quartz.  Fairly hard, amethyst is a 7 on the Mohs hardness scale which has a range from 1 (softest) to 10 (hardest).  Crystals of the mineral often form in clusters, which are also called druze, and also commonly form in geodes.  The purple color of amethyst is due to the presence of ferric iron (Fe3+) in the quartz crystal and can range from light to dark.  When heated, amethyst will turn brown, into citrine.

Amethyst is considered a semi-precious gemstone that is most commonly used in jewelry and for collecting.  Beautiful samples of amethyst can be found in Brazil, Mexico, Uruguay, Russia, India, Sri Lanka, and the United States.

Aquamarine – March’s Birthstone

Aquamarine is a pale blue form of the mineral beryl.  Aquamarine crystals can occur in such rocks as granite and pegmatite.

These beautiful gemstones have a glassy luster (shine) and are either translucent or transparent.  These properties make aquamarine a prized stone for all types of jewelry.

Diamond – April’s Birthstone

Did you know that pencil lead and diamonds are made of the same thing?  It is hard to believe but they are both made of carbon!  The carbon forms in different crystal types or shapes, which is why they are different.  Diamond is the hardest mineral, being a 10 on the Mohs hardness scale.

Diamonds form in igneous rocks called Kimberlites and Lamproites. These igneous rocks are typically rich in the mineral olivine and derive from mantle rocks known as peridotites. The peridotite rocks melt deep below the surface (between 90 and 280 miles) of the Earth then rise through cracks in the surrounding rock forming pipe-shaped intrusions. As the magma pushes its way through the cracks, some of the surrounding rocks break off and mix into the liquid magma. Over time, (millions of years) the magma slowly cools into rock with large crystals. Sometimes these crystals include those wonderful gemstones we know as diamonds.  This photo shows cores of kimberlite rock from a drilling and exploration project. The rocks cores are stored these long, then boxes for examination. Geologists store the cores in order as they pull them from the ground so that they can view the rocks in one long string and see exactly what is present below the land surface.

The largest diamond ever found is over 7,000 carats which is about the size of your two fists put together.  Because of their beauty and strength, diamonds are used for a wide variety of products from jewelry to industrial cutting blades. The photo at the top left shows a group of different sized diamonds which have been cut and faceted.

Emerald – May’s Birthstone

Emerald is a green form of the mineral beryl.  Emerald is a hard gemstone that has a glassy luster (shine) and is either translucent or transparent.  The elements chromium and vanadium give emerald its green color.  Emeralds are one of the most rare and prized gemstones and can be worth more than diamonds if they are pure.

Pearl – June’s Birthstone

Pearls are a beautiful organic gemstone which is formed in a variety of colors and shapes.  Pearls form inside of mollusk shells such as oysters and mussels.  This unique gemstone is made of primarily the mineral aragonite.  Aragonite is the mineral that lines the inside of the mollusk shell.  An organic substance, called conchiolin, is also known to line the inside of the shell.  When shell linings are made of aragonite and conchiolin together, it is called mother-of-pearl.

To form the gemstone pearl, a grain of sand must get trapped inside the mollusk shell.  The aragonite forms in circles around the sand grain.  It can take between 2 and 8 years for a large pearl to be formed.  Fairly soft, pearls are a 3 on the Mohs hardness scale and have a white streak. The luster, “pearly,” is often used to describe the look of other minerals with similar outward appearance. Pearls can form in both freshwater and salt water and can be round and smooth to oblong and uneven.  Common colors of pearls include white, cream and black; however, other colors such as blue, yellow, gray, green, light purple and mauve can also be found.

Ruby – July’s Birthstone

Rubies are one of the hardest known minerals.  With a hardness of 9 on the Mohs scale, it is only softer than a diamond.  Rubies are known for their beautiful red color.  A ruby is a variety of the mineral corundum.  The gemstone sapphire is also a variety of corundum and comes in many colors, except for red.  Rubies have a glassy luster which makes them shiny.  Rubies are most commonly used for jewelry.  Rubies are commonly mined in Myanmar, Thailand, Kenya, the United States, Sri Lanka and Tanzania.  In 2005, a 440 carat ruby was discovered and thought to be one of the largest gems found to date.

Peridot – August’s Birthstone

Peridot (“pair-a-doe”) is the August birthstone.  This lovely green gemstone is a variety of the mineral olivine. Peridot gets its green color from the presence of iron in the crystal’s structure.  The amount of iron present determines the intensity of the green color such that the higher the iron content the darker the green color. Interestingly, peridot is only found in the color green whereas most other minerals can be found in more than one color.

Although olivine is common in igneous and metamorphic rocks, the gemstone quality version is much rarer. Arizona has one of the more abundant sources of peridot but the quality is not as high as in other regions, such as Egypt, Myanmar, Burma and Pakistan, which have smaller amounts of the gemstone. The Smithsonian Institution has a gemstone from Egypt that is over 310 carats, which is largest peridot ever found.

Sapphire – September’s Birthstone

Sapphires are a blue form of the mineral corundum.  When corundum is red, it is called a ruby.  Corundum is one of the hardest known minerals with a hardness of 9 on the Mohs scale.  The gemstone sapphire is usually known for its spectacular blue color, but can also come in many other colors, except for red.  Sapphires have a glassy luster which makes them shiny and are most commonly used for jewelry.  One of the largest sapphires in the world is called the “Logan Sapphire” and is over 422 carats.  Many beautiful specimens of sapphire are mined in Myanmar, Madagascar, Kashmire, and Sri Lanka, and Australia.

In the United States, sapphires and rubies can be found in the area of Franklin, North Carolina, which is a popular area for mines.

Opal – October’s Birthstone

Opal is a unique mineral because it forms as a gel in cracks of many different types of rocks. However, opal is most often found in rocks like basalt, rhyolite, sandstone and limonite.  High water content is a trademark of the opal.  Up to 20% of an opal can be water.  Opals come is a wide variety of colors including white, reds, greens, pinks, browns, and blues to name a few.  Most opals do not have a specific shape, however, “precious” opal which are used for jewelry do have a round structure to them. Almost all of the world’s opal supply comes from Australia.

Topaz – November’s Birthstone

The November birthstone is topaz.  Topaz is a unique gemstone which comes in a huge variety of colors such as orange-yellow, colorless, light blue, pink, brown and green.  Topaz has a hardness of 8 on the Mohs Hardness Scale and a glassy luster.  Igneous rocks are the most common type in which to find topaz gemstones.  Topaz is used for jewelry in its variety of colors.

Turquoise – December’s Birthstone

The December birthstone is Turquoise, a blue to green minerals which is moderately hard and typically shows no specific crystal structure. Turquoise is a 6 on the Mohs Hardness Scale of 1 to 10, has a pale blue to white streak, and a waxy luster. “Cryptocrystalline” is the term often used for minerals like turquoise where the crystals are so small that they cannot be seen.  Turquoise can be nicely polished and is therefore, used often in jewelry.

Free STEM Resources Available from Mini Me Geology

FREE Resources from Mini Me Geology_pin

I built Mini Me Geology on the idea that science and fun should go hand-in-hand for kids. From the first day I started the business, I wanted to have a supply of free resources for students, teachers and home school parents to supplement their lessons and the use of our kits. Today, our company offers a wide array of free resources including educational articles, rock and mineral identification flow charts, instructions on sample identification, experiments, activities, novels with a touch of real science and science fiction, and much more.

I hope you take advantage of these free resources to enjoy some with your kids and help them learn a little bit about the science of geology without putting a strain on your budget.

Rock & Mineral Fun Book

Mini Me Geology’s Rock & Mineral Fun Book is a free pdf eBook with puzzles, coloring pages, birthstone facts, experiments, rock and mineral identification information, and a copy of our free science fiction, time travel novel for kids. You can get your copy of the Rock & Mineral Fun Book by signing up for our newsletter. A link to download your eBook will be sent directly to your inbox and you can print the games and activities as many times as you like.

Crossword and Word Find Puzzles

Our site has an entire page dedicated to downloadable geology themed crossword and word find puzzles. Just click on the name of each puzzle, download it to your computer and print!

Viktor’s Ice: The Magic is Born Novel

In this prequel novella to the Crystal Cave Adventures series, you will discover the secret of the crystal cave from the moment the magic is born. If you have read books in the series or if you are just starting with our adventures, you will love this story of how the magical crystal cave came alive and helped Mr. M find his first rare mineral. Get your copy of Viktor’s Ice today.

Ask-a-Geologist Questions & Answers

Our Mini Me Geology YouTube channel features questions and answers submitted by our site visitors. You can browse through our videos and find the answer to some great questions. We are always looking for more great questions to answer, so send us your questions, and look for a video answer on YouTube and our Blog.

Rock & Mineral Identification Charts

Do you have rock and mineral samples and are unsure of their names? The Dig Into Geology section of our website features downloadable identification flow charts for minerals, igneous rocks, sedimentary rocks, and metamorphic rocks. These charts have the most common rocks and minerals on Earth.

Visit Our Blog for Experiments, Articles and Interesting Geology Information

The Mini Me Geology Blog has approximately 250 articles including details about unique geological locations, fun experiments, interesting activities and much more! You may enjoy some of these popular posts:

What Mineral is My Birthstone and what are its Properties?
How to Draw a Cross-Section from a Topographic Map
Science Projects You Can Perform With Edible Materials
Growing Rock Candy Crystals: A Sweet & Fun Science Experiment
‘Bread Rocks’ Make a Fun Metamorphic Science Experiment
Ask-a-Geologist Video #11: Why do pumice and scoria have holes and granite does not?
Why do sandstone rocks sometimes have holes in them?
Growing Salt Crystals is a Fun Geology Experiment for Kids (and adults, too)!
The Fizz Test for Limestone & Marble Rocks
How to Perform the Geology Fizz Test without Hydrochloric Acid
Ask-a-Geologist #4: Why do geologists test rocks for calcite?
10 Ways to Decorate your Home or Office with Rocks and Minerals
Piper reviews the Colossal Rock and Mineral Kit
The Geometry of Minerals: How Some Crystals Form Unique and Beautiful Mathematical Shapes
A Metamorphic Rock Lesson So Yummy You Can Eat It!
Loess – the Earth’s most fragile rock!
Rock Salt or Halite It’s one Great Mineral
Fluorite – A Special Mineral of Many Forms and Colors
A Rock Weathering Experiment You Can Do In Your Kitchen!
Ask-A-Geologist #8: What is obsidian rock used for?
Ask-a-Geologist #22: What are some common household items made of rocks and minerals?
Glaciers are Awesome!
Ask-a-Geologist #10: What Are The Remains Of Once Living Organisms Found In Sedimentary Rocks?
Rock & Mineral Coloring & Activity Book – Now in Print
Do You Have a Sandstone or a Quartzite?

Explore the Mini Me Geology blog today and learn more about this fascinating science!

Contact Us for More Great Ideas

I hope you take advantage of all of the free resources Mini Me Geology has to offer. If you have questions about anything on our site, please contact us!

Fluorite – A Special Mineral of Many Forms and Colors

Fluorite is a unique mineral that forms in more colors than any other mineral on Earth. The most common colors are blue, red, purple, yellow, green, and white. In developing the Mohs Scale of Mineral Hardness, Friedrich Mohs chose fluorite as the example mineral for the hardness of four (4) on the scale.

Italian mineralogist Carlo Antonio Galeani Napione named the mineral in 1797. The name fluorite is derived from the Latin word “fluere” which means “to flow.” Fluorite was often used as a flux in iron smelting, which is believed to be the reason behind the name choice.

Fluorite often forms in low to high temperature hydrothermal veins inside rocks, especially those containing lead and zinc minerals. It is also present in some igneous and metamorphic rocks. Fluorite is often found with other minerals such as galena, calcite, quartz, sphalerite, and borite. Crystals of fluorite can form in cubes (squares) or octahedrons (diamond) shapes.

Common Properties of Fluorite

Formula: CaF2
Other Names: Fluorspar
Color:  Blue, Red, Purple, Yellow, Pink, Champagne, Brown, Green, or White
Hardness:  4 on Mohs Hardness Scale
Streak:  White
Luster:  Glassy to Dull
Density:  3.175 – 3.56 g/cm3
Crystal Shape: Cubes, Octahedrons, Dodecahedrons. Sometimes twinned crystals occur.
Fracture: Conchoidal to splintery
Cleavage:  Perfect Octahedral

Beautiful samples of fluorite exist in Germany, Italy, Switzerland, England, Mexico, Canada, and the United States. Fluorite is a common component in enamels, hydrofluoric acid, cooking utensils, telescopes, camera lenses, jewelry, and home décor items.

Fluorite Mineral

Fluorite Mineral Fun Facts

  • Fluorite crystals often grow together which is called “twinning.”
  • Fluorite crystals will fluoresce under ultraviolet light.
  • Jewelers sometimes facet fluorite crystals and use them as imitation diamonds although it is a much softer mineral making fluorite less ideal as a gemstone.
  • In addition to forming cubes and octahedrons, fluorite can occur in bands. One of the most famous forms of banded fluorite is called Blue John and found in Derbyshire, United Kingdom.
Fluorite Octahedrons

A Spectacular Rare Form of Fluorite

A rare type of striped, or banded, fluorite is the Blue John Fluorite found in the Blue John and Treak Cliff caverns in England. These caves are located in the Peak District in England near the town of Castleton, Derbyshire. The caverns formed within limestone strata that deposited in deep ocean waters millions of years ago. Layers of shale and some gritstone, a type of coarse sandstone common in this area, cover the limestone. The geology of the Blue John Cavern is fascinating and discussed further in a separate blog post.

Blue John Fluorite

This rare form of fluorite is so fascinating that it was the catalyst for an entire book series titled, the Crystal Cave Adventures. This book series starts when teenagers Emma and Brody fall through a time-traveling cave and land in 1775 England to steal a sample of the rare mineral for their friend, geologist Mr. M (aka Heath Matthews). Mr. M’s stunning rock and mineral collection is scheduled for national display when a thief breaks into his house and destroys all of his samples and maps. Emma and Brody vow to help rebuild the collection, later discovering the secret, magical time-traveling cave that Mr. M used to collect his unique samples. With one simple step, the adventure begins.

Blue John's Cavern

From the book, Blue John’s Cavern:

         “The Blue John Fluorite is one of the rarest forms of a common mineral. Its name comes from the French words ‘Bleu Jaune’ which translates into English as ‘Blue-yellow.’ The Blue John form of the mineral is located in a hillside near a large mountain called Mam Tor, which is just outside of the town of Castleton,” Mr. M said. He stopped walking and opened a long tube he was carrying and removed a street map. Mrs. M, Emma, and Brody held the map open as he pointed to a solid green area that showed the grassy hills of Derbyshire, England. Nestled in the rolling hills were the town of Castleton and a historic castle called Peveril. “The fluorite is found in two caves to the west. One cave is named Treak Cliff, and the other is called Blue John. Inside the caves, the fluorite runs in veins that are as thick as your fist. The fluorite always has bands of colors like blue and purple or white and yellow.”

         “Because of its beauty,” he said rolling the map and placing it back into the cylinder, “the Blue John Fluorite was largely mined and used to make jewelry, statues, and vases.” The group kept walking. Soon they were standing in front of a thick, woven mass of vines that looked like a door covering. “This is where you’ll find the Blue John Fluorite,” Mr. M said.

You can find out more about the first book in the Crystal Cave Adventures book series, Blue John’s Cavern, on our website.

Check out our website for great cubic fluorite samples and fluorite octahedrons. If you have questions about fluorite or any of our samples, contact us! We are happy to help you discover new, exciting samples for your collection.

The Best Sciences Gifts for Everyone on Your List

Whether it is Christmas, Hanukkah, birthday or another special event, finding the perfect gift is part of the excitement. We know you want to give a great gift that is fun and unique. As parents, we often want gifts that are also “good” for children because they are healthy, engaging, or educational. For the adults on our list, we are always searching for something new and different that will be a happy surprise. Mini Me Geology has the perfect mix of ideas for everyone on your list from your youngest rockhound, to the teenagers in your life, and adult friends and family who love collecting beautiful samples and crystals for spiritual well-being.

Best Science Gifts for Toddler Rockhounds

Rock & Mineral Coloring & Activity Book

Kids under six years old are curious when it comes to science and educational toys but they are still at an age where small parts in some science kits might be a choking hazard if the kids are left unattended. That is why we created the Rock & Mineral Coloring & Activity Book for kids! This fun book is loaded with 78 pages of childhood fun including Drawing Pages, Coloring Pages, Roc-Tac-Toe, Foursquare, Word Scrambles, Crossword Puzzles, Word Finds, Mazes, Creative Writing Stories, and Make-a-Word Games. The Rock & Mineral Coloring & Activity Book was designed with fun activities that also help children become interested in science.

The Best Science Gift for 6 to 12-Year-Olds

Kids that are 6 to 12-year-olds are the perfect age for beginning science kits. In fact, the child who inspired the launch of Mini Me Geology was six years old when he first covered the wonder of rocks and minerals. As a mother and geologist, the owner of Mini Me Geology set out specifically to design kits for this age group so that kids could learn about rocks and minerals but also explore through fun activities such as experiments, puzzles, mazes, coloring pages, writing activities, and creative crafts.

Be a Rock Detective!

Rock Detectives Kits

The Rock Detectives line of kits is specifically designed for the 6 to 12-year-old age group. There are six kits in the series, each with its own detective’s theme. The kits include Mineral Mission, Crystal Experiments, Crystal Geometry, Metamorphic Mystery, Sedimentary Sleuthing, and Igneous Investigation.

Each of these kits has six or seven samples that were specifically picked to fit the theme and a hand magnifier for viewing the samples up close. Each kit has a 30-page PDF eBook that is included on a CD. If you don’t have a CD player that is no problem! We have download links for all of the eBooks and you are able to print as many copies as you like for all the kids in your household. The best part of these kits is that we designed them so that the kids can work on some of the activities alone and perform others with their parents, teachers, and groups just like real scientists!

Junior Rock & Mineral Kits for Kids

Junior Mineral Kit

The My Rockin’ Collection Junior kits series is a favorite for kids between the ages of 6 and 12. Housed in sleek tubes, the junior kits are easy to store between uses, which keeps the rocks off the floor and safe. The My Rockin’ Collection Junior kits are one of our best-selling lines because kids can explore the samples on their own or with a parent. There are four kits in this collection including Minerals, Igneous Rocks, Sedimentary Rocks, and Metamorphic Rocks. Each kit has 10 of the most popular samples from the category and an identification poster that includes fun information, identification tips, and pictures of each of the rocks to help your kids identify all of the samples in the collection.

The Best Science Gifts for Teens and Young Adults

Older kids who are interested in science really love the idea of experimenting with the samples. We designed several collections and kits that allow them to do just that.

Explore the Rock Cycle

The Rock Cycle Kit is one of our most popular kits for teens. This fantastic kit has 20 rock and mineral samples, a hand magnifier for examining the specimens, and a PDF eBook full of information about each of the samples, the rock cycle and how it works throughout the Earth, plus activities, experiments, and games. The Rock Cycle Kit is great for kids who are interested in becoming a scientist because the activities of the kit help them develop a fascination with science and the critical thinking skills with a need for any type of science in the future.

Testing and Experiment Kits

Mineral Observation, Hardness & Streak Testing Kit

Our most popular kit for teens is the Mineral Observation, Hardness, and Streak Testing Kit. This kit is based on the Mohs Scale of Mineral Hardness and includes eight samples from the scale, identification accessories including a white streak plate, a black streak plate, and information cards that explain how to use all of the identification tools.

Popular Science Gifts for Kids of Any Age

Many of the kits we design can cross age groups and uses. We love helping kids explore science at home and helping teachers and homeschool parents in the classroom.

Mineral Madness Kit

Mineral Madness STEM Geology Kit

Mineral Madness is our newest kit for kids and teens. This fun kit has 15 minerals, a white streak plate, and an information brochure with pictures and details about each of the samples, their properties, and fun facts so your kids learn to identify the samples and recognize them in nature.

Earth’s Treasures Geology Sifting Cups

Earth's Treasures Geology Sifting Cup

A favorite of gift-givers and birthday parties, the Earth’s Treasures Geology Sifting Cups are filled with real beach sand, rocks, minerals, and fossils. As kids sift the sand, they find their treasures. Each Earth’s Treasures Geology Sifting Cup is slightly different making them fun to collect and the perfect party favor.

Crack-Your-Own Geodes

Crack Your Own Geodes are a fan favorite for all ages (adults, too). We carry only the largest geodes available that are filled with beautiful quartz crystals. You will love to see the excitement on your kids’ faces as they crack open the rocks to reveal the shimmering quartz crystals inside.

The Colossal Rock & Mineral Kit

Our largest kit is perfect for ages six through adult. The Colossal Rock & Mineral Kit is a two-box kit that includes 10 samples each of minerals, igneous rocks, sedimentary rocks and metamorphic for a total of 40 samples. White and black streak plates, a hand magnifier and four identification posters are also included in the kit. Kids will learn about the color, streak, crystal shape, hardness, luster, special features, common locations and uses of minerals while discovering and the different colors, textures, mineral content, uses and properties of rocks as you observe and test your new samples. The colossal rock and mineral kit is house in plastic storage boxes which helps keep everything organized and neat. This is the perfect science gift for future scientists and engineers!

Best Gifts for Adult Rock Collectors

Many adults enjoy collecting unique and interesting rock and mineral samples. Mini Me Geology strives to find the best samples available for our customers. Our collection includes over 120 rocks and minerals so you have an amazing selection to choose from. Each sample comes with an information card that details the properties of the sample, common uses, specials features, and popular collection locations.

Best Gifts for Everyone Who Loves Healing Crystals

Using crystals in meditation and healing practices is very popular today. We have curated a wonderful selection of rough, natural minerals and crystals that pair with each of the body’s chakras so you can create your own personalized collection. If you prefer a pre-made kit, the Natural Chakra Crystals kit has eight wonderful crystals that include one for each chakra and quartz to amplify the power of the others. The included information brochure provides details about each sample and the related chakra and pictures of the crystals for easy identification.

Science gifts are perfect for everyone on your list because they are fun, exciting, and unique. If you have questions about specific kits and samples, contact us and we will be happy to help.