Rocks and Minerals We Love: GYPSUM MINERALS

Gypsum is one of the most unique minerals found in the world with beautiful samples forming in numerous countries and settings. Some minerals, like gypsum, have the fascinating ability to take on different shapes depending on the environment where they grow.

The name Gypsum comes from the Greek word gypsos, which means plaster and mentions of the minerals are known beginning approximately 300 BC. Around the globe, gypsum forms in massive chunks, clear crystals, and as fibrous bundles. Gypsum is a soft mineral and was chosen as an example mineral by Friedrich Mohs for this Scale of Mineral Hardness.

Physical and Chemical Properties of Gypsum

Gypsum is a soft, evaporite mineral that you can easily scratch with your fingernail. Because of its unique properties, gypsum is great for school projects and in-class experiments. Here are some of gypsum’s interesting physical and chemical properties.

  • Chemical Formula: CaSO4  2H2O
  • Color:   Colorless to white but may appear with shades of pink, tan, yellow, blue, brown, red and gray from the presence of impurities in the mineral.
  • Hardness:                 2 on Mohs Hardness Scale.
  • Streak:                     White
  • Luster:                      Glassy, Silky, Pearly, or Waxy
  • Cleavage:                 Perfect
  • Fracture:                   Splintery or Conchoidal
  • Specific Gravity:       2.312 – 2.322
  • Crystal System:        Monoclinic
  • Crystal Shape:          Thick tabular to lenticular crystals. At times, maybe prismatic. Varieties can for rosette clusters, granular masses, and fibrous masses.

Varieties and Forms of Gypsum

Massive Gypsum Minerals Sample

Gypsum is very common throughout the world and has many varieties that can form as single crystals or clusters of many crystals in varying shapes. Massive Gypsum is a common variety that many people think of when they hear of the mineral.

Gypsum is also known to form “roses” which are clusters of lenticular (lens-shaped) crystals. Alabaster is a fine-grained massive form of the mineral that is typically white in color. Due to its beautiful hue and softness, alabaster is a favorite sculpture medium for artists.

Twinned Gypsum Roses Crystals
Twinned Gypsum Roses

Selenite is a clear, crystal form of gypsum. Clear selenite often has good cleavage planes and a pearly luster. Selenite was named after the Greek word for moon because of the “moonlight” appearance when light reflects off of the crystal surface.

Satin Spar is a white, fibrous form of selenite which forms in long strands, which grouped together, form “sticks.” Satin Spar selenite appears and feels silky.

Satin Spar Selenite Stick Mineral
Satin Spar Selenite Stick

Uses of Gypsum Minerals

Gypsum is one of the most useful minerals on earth. From ancient times to now, people have found ways to use gypsum in a variety of products including:

  • Paint
  • Tile
  • Drywall
  • Blackboard Chalk
  • Fertilizer
  • Plaster of Paris
  • Food
  • Hair Products
  • Skin Cream
  • Environmental Restoration
  • Dentistry Impressions
  • Sculpture (Blocks of Alabaster)
  • Metaphysical practices (selenite variety typically)

9 Gypsum Mineral Fun Facts

  1. Gypsum is the most common mineral on earth containing sulfur.
  2. Gypsum can form very large crystals, the largest known being 39 feet long found in the Cave of the Crystals in Naica, Chihuahua, Mexico.
  3. Gypsum often forms in sedimentary environments like lakes and oceans when the water evaporates leaving the mineral behind.
  4. Gypsum will slowly dissolve in cold water.
  5. Gypsum has water in its crystal structure. When the mineral is heated, it will lose the water and transform into bassanite (plaster) and then anhydrite.
  6. Because Gypsum is very soft and has perfect cleavage, it is very difficult to cut gypsum with facets. This is why gypsum jewelry is not common.
  7. White Sands National Monument in New Mexico is made of rare gypsum sand. Gypsum typically dissolves in water rather than breaking down into sand particles, which is why the White Sand National Monument is so special.
  8. Gypsum often forms with other minerals like halite (table salt), sulfur, calcite, quartz, pyrite, dolomite, fluorite, and azurite.
  9. A sample of gypsum will fluoresce with colors of light blue, yellow and golden yellow under a UV light.

Locations of Gypsum Minerals

Gypsum is found all over the world. Some of the largest and most interesting deposits are located in Mexico, Brazil, Italy, Russia, France, Canada, and the United States.

Explore Gypsum and Add to Your Collection

Mineral Madness STEM Geology Kit
Mineral Madness Kit

Mini Me Geology has fabulous samples of gypsum and satin spar selenite available as individual samples and in kits. These great samples are perfect for conducting experiments and adding to a growing collection. Gypsum samples are included in our: My Rockin’ Collection Deluxe Kit, the Junior My Rockin’ Collection Kit, the Colossal Rock and Mineral Kit, Mineral Madness, and the Mineral Observation, Hardness & Streak Testing Kit. If you have any quesitons about gypsum or any of our awesome samples, let us know!

Celebrate Easter & Earth Day Together This Year

Easter Mineral Bundle
Easter & Earth Day Mineral Bundle

Liven up this holiday season by filling those Easter baskets with 12 great mineral samples. In 2019, Easter and Earth Day are April 21st and 22nd. We created a group of 12 pretty and popular minerals samples that are sure to delight every kid in your life. Plus, becuase we know how great Easter candy can be, each set of minerals also comes with a Rock Candy Lollipop!

The Easter Mineral Bundle includes:

12 Mineral Bundle + Rock Candy Lollipop
  1. Clear Quartz Point,
  2. Fluorite,
  3. Sodalite,
  4. Selenite Stick,
  5. Rose Quartz,
  6. Blue Calcite,
  7. Tourmaline,
  8. Citrine,
  9. Red Jasper,
  10. Amazonite,
  11. Red Garnet, and 
  12. Lepidolite.

Get your mineral bundle today!

Throw a Rock Detectives Geology Birthday Party for Your Kids with this Party Plan

Is your little one having a birthday? Do they love rocks and minerals? Then throw them a Rock Detectives Geology Birthday Party!  This party idea is based on Mini Me Geology’s Rock Detectives line of kits to give your child and their guests hours of fun.

Below you will find a Rock Detectives Geology Birthday Party Plan with ideas that will help you design a party full of rock and mineral identification activities, geode cracking, panning for minerals, and storage box creation. Throwing a party is simple, choose the Rock Detectives kits that you want to use as the theme for the party such as minerals, crystals, rocks, or all of them.  Your kids can learn about Metamorphic Mysteries, become a Sedimentary Sleuth or solve an Igneous Investigation. You can also design your party around our Crystal Geometry and Crystal Experiments kits or go on a Mineral Mission.

Our Rock Detectives Birthday Party Invitations and Activities eBook includes instructions for panning, geode cracking, storage box creation, and rock bingo as well as invitations to send to your guests! In addition to the activities in the party eBook, each Rock Detectives Kit comes with its own CD with an eBook full of activities, puzzles, and experiments that you can use at your party.


Activity #1:  Arrival Puzzles & Coloring Pages

Each party pack of Rock Detectives kits comes with a free parent copy of the Rock Detectives eBooks so that you can print and prepare the party activities from the kits before the kids arrive. Each kit has word puzzles, mazes, and coloring pages that you can give to your party guests to occupy them as other guests arrive.

Activity #2:  Create-Your-Own Rock Storage Box

A good geologist always has a way to carry their samples. Create fun storage boxes out of inexpensive items from around your house. Instructions are provided on the Rock Detectives Party eBook. You can use plastic boxes or egg cartons to make great boxes with individual slots for different samples.

Activity #3:  Sample Identity Detection

Print the sample identification and activity pages from the Rock Detectives eBook and let your party guests follow the clues to identify the name of each sample in their Rock Detectives kit. Each kit comes with a hand magnifier to help see the details! We recommend that you use one Rock Detectives kit for every two to three kids at the party so they each have samples to identify and test.

Earth's Treasures Geology Sifting CupActivity #4:  Panning for Rocks, Minerals & Fossils

Mini Me Geology’s new Earth’s Treasures Geology Sifting Cups are a fun party activity and a great take-home gift. Each 8-ounce jar is filled with natural beach sand, rocks, minerals, and fossils. No two jars are exactly the same so each child has a unique set of samples. To find your hidden treasures, simply pour the contents through a beach sifter as real geologists do. The sand will fall through leaving your goodies behind.

If you don’t have a beach sifter on hand have the kids create their own by layering several layers of aluminum foil and then rolling the ends together to make a bowl. Using the sharp tip of a pencil, poke small holes in the foil to create a homemade sifter that will allow the sand to fall through and keep the treasures on the foil.

If you prefer to make your own sifting gifts, use a small bucket or mason jar and fill it with a mixture of sand, rocks, minerals, and fossils.  Instructions are provided on the Rock Detectives Party eBook. We have bulk rocks and minerals and fossil shark teeth for your panning buckets.

Activity #5:  Geode Cracking

All good geologists break open rocks to see the inside. Kids love to crack open large geodes to see the crystals inside. Instructions and safety precautions are provided in the Rock Detectives Party eBook. Our large geodes make great take-home gifts for your party guests.

Activity #6:  Geology Experiments

All good geologists love experimenting with their samples. Each Rock Detectives kit includes instructions for experiments that you can do during the party like growing sugar and salt crystals, creating metamorphic rock cookies, and much more. Don’t worry if you run out of time, you can print the instructions and let the guests take them home.

Activity #7: Wrap Up with Rock Bingo!

Play Mini Me Geology’s Rock Bingo to wrap up your party. The bingo game is included in the Rock Detectives Party Invitations and Activity eBook. A great gift for winners is rock candy from your local candy store. If you can’t find the candy locally, give us a shout and we can point you to some online sources for bulk rock candy.

Get started planning your party today! If you have questions about our kits or how to throw a successful party, contact us.




Happy Birthday Friedrich Mohs!

Friedrich Mohs Birthday

Today is German Geologist Friedrich Mohs’ Birthday!

Geologist Friedrich Mohs was born on January 29, 1773, in Gernrode, Germany. Born Carl Friedrich Christian Mohs, he was a geologist and mineralogist who during his career worked at a mine, as a mineralogist for a private collector, and as a geologist for a museum. During his career at the museum, Friedrich began to identify minerals using their physical properties. One of these physical properties was the hardness of a mineral, which led him to create the Mohs Scale of Mineral Hardness in 1812. Friedrich Mohs died on September 29, 1839, at the age of 66.

Still today, we use mineral hardness as a clue to the identity of a sample. The Mohs Scale of Mineral Hardness is a relative hardness scale with 10 mineral samples and several common items such as glass, fingernail, and a pre-1981 penny. Each item on the scale has a specific hardness. Talc, number one on the scale is the softest and diamond, number 10, is the hardest. The Mohs mineral scale and common object are:

Mohs Scale of Mineral Hardness

In this video we discuss how to use the Mohs Scale of Mineral Hardness with your own samples.

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.

Mini Me Geology’s Mineral Madness is the Perfect STEM Kit for Kids

Mini Me Geology is proud to announce their newest geology kit, Mineral Madness. With the importance of STEM education rising, we are dedicated to developing kits that allow children to explore science with quality hands-on samples, accessories and information. The Mineral Madness kit has fifteen (15) mineral samples, a white streak plate, and a mineral identification brochure. Kids are challenged to identify each sample using the streak plate, visual observations and the information in the brochure along with support information from the Mini Me Geology website. After kids determine the name of the sample, the brochure provides additional information about the properties, use, and common locations for each mineral type.

This kit is perfect for kids starting out in geology who are intrigued by the colors, shapes and unique features and older students who are honing their identification skills. Mini Me Geology’s in-house geologist designed this kit so it is economical for parents and schools while providing a generous variety of sample types for kids to explore. The 15 included minerals are:

  • Augite,
  • Azurite,
  • Beryl,
  • Calcite,
  • Fluorite,
  • Garnet,
  • Gypsum,
  • Halite,
  • Kyanite,
  • Magnetite,
  • Malachite,
  • Olivine,
  • Milky Quartz,
  • Amethyst, and
  • Sodalite.

A 2” x 2” white streak plate is included so that students can test the color of the streak to help in the mineral identification process. The brochure includes information such as color, luster, hardness, streak, and features, which will help in the identification process as well as a picture of a typical sample. Mini Me Geology offers free resources in our Dig Into Geology section of the website including how to videos and printable identification flow charts to assist you they work to identify your new samples. Follow these links to download your own free identification charts and learn how to properly test your mineral samples.

Download a Mineral Identification Flow Chart

Video Article:  How to Determine Hardness Using the Mohs Hardness Scale

Video Article:  How to Perform Streak Test

Join in our Mineral Madness and get your kit today! If you have questions about the kit or any of the samples, get in touch.

Special Offer for newsletter subscribers!

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 and coloring pages, experiments, rock and mineral identification flow charts and image galleries, birthstone details and a copy of Viktor’s Ice, the first book in the Crystal Cave Adventures rock collecting, time travel series for kids.

Mini Me Geology Rock Detectives Kits for Elementary and Middle School STEM activity fun!

The Rock Detectives Kits are absolutely perfect for kids who are starting out in science. These kits are great for STEM activities and they can help kids who are resistant to science become more interested through the experiments, activities, puzzles and coloring pages. This video gives you a little more insight into these fun kits that we developed just for kids!

Kids will have hours of fun with the Mini Me Geology Rock Detectives Kits. These fun kits come complete with six or seven cool rock or mineral samples, a hand magnifier and a mini CD with 30 pages of mineral information, sample identification activities, puzzles, coloring pages and experiments. Other fun activities on the CD include creating your own adventure story, making a personal geologist field notebook and your very own rock collection box. No CD tray? No problem! Each pdf eBook is downloadable, too.

Our Rock Detectives kits are best for ages 6 through 12.

Choose from:

  • Mineral Mission
  • Crystal Experiments
  • Crystal Geometry
  • Igneous Investigation
  • Sedimentary Sleuthing
  • Metamorphic Mystery

If you’re looking for more information about geology, check out the Dig Into Geology section at

Do you have questions about geology? Submit your Ask-a-Geologist question and we just may answer you in our next video! Submit your questions here:

For more great geology information, visit

Join our company newsletter for fun geology information and great savings on your favorite rocks, minerals, and fossils!

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Ask-a-Geologist Your Questions about Rocks, Minerals, Fossils!

Do you have questions about geology, rocks, minerals or fossils? We would love to answer your questions in our next Ask-a-Geologist question and answer video. We would love to hear from kids, teachers, homeschool parents and anyone who just loves Earth Science. Submit your Ask-a-Geologist question today:

Stay in touch with all of the latest from Mini Me Geology by joining our newsletter!

Rock & Mineral Poster Sets for Home, Classrooms & Schools – Perfect for STEM Lessons

At Mini Me Geology we have a great selection of geology products that are perfect for all of your STEM lessons. This fun rock and mineral poster set has four posters for Minerals, Igneous Rock, Sedimentary Rocks, and Metamorphic Rocks. You can find these on our website.

These are the same flyers included in our Junior kits and our Colossal Rock and Mineral Kits and are perfect if you have a rock collection or if you are looking for an inexpensive way to introduce rocks and minerals as a hobby to your children or in school for earth science lessons. Each flyer features 10 of the most common samples found in natures. Flyers include minerals, igneous rocks, metamorphic rocks and sedimentary rocks.

Mineral flyer includes: augite, calcite, fluorite, gypsum, halite, kyanite, magnetite, olivine, amethyst, and sodalite.

Igneous Rock flyer includes: basalt, granite, monzonite, obsidian, pegmatite, pumice, rhyolite, syenite, trachyte and volcanic breccia.

Sedimentary Rock flyer includes: arkose, bituminous coal, conglomerate, coquina, loess, fine-grained limestone, banded sandstone, shale, siltstone, and oolitic limestone.

Metamorphic Rock flyer includes: amphibolite, gneiss, hornfels, pink marble, phyllite, quartzite, schist, slate, garnet schist, and anthracite coal.

Stay in touch with all of the latest from Mini Me Geology by joining our newsletter!


Crystal Cave Adventures Blends English Language Arts and STEM into an Exciting Novel Series for Kids

Crystal Cave Adventure NovelsThe release of the Crystal Cave Adventure series is an exciting step that blends fun adventure stories with science. In today’s world when Science, Technology, Engineering, and Math (STEM) curriculum is all the rage, a novel series that can transport kids to a story that is fictional yet has a touch of real science woven throughout the series is a welcome change to many children.

The series, which just released its third book, tells the adventures of young teenagers Emma and Brody as they travel through time to collect rare mineral samples from around the world. In Book 1, Blue John’s Cavern, Emma meets Brody, her new neighbor in Diamond Falls, West Virginia. When Brody discovers that Emma loves rocks and minerals, he offers to take her to meet the famous geologist who lives across the street, Heath Matthews. Mr. M, as the kids call him, is preparing his prized rock and mineral collection for a display at the State’s Natural History Museum. When a thief breaks into the Matthews’ home and destroys the collection, Emma and Brody offer to help recollect the samples. Mr. M gladly accepts the help and then sends Emma and Brody on the wildest ride of their lives when they learn the secret of his collection. The magical, time-traveling Crystal Cave.

Currently, the series consists of:

Book 1, Blue John’s Cavern. After accepting their offer to help, Mr. M promptly sends Emma and Brody is Castleton, Derbyshire England in 1785 to collect a sample of the rare Blue John Fluorite. You can read the full book blurb here to learn more about this amazing adventure and the mysterious young girl who helps them along the way.

Book 2, Rusher’s Gold. Emma and Brody travel to the California Gold Run in 1851 to collect a sample of pure gold but when their plan goes awry they learn that their actions in the past can have dire consequences to their future. You can read the full book blurb here.

Book 3, Black’s Opal. Emma and Brody travel to Lightning Ridge, Australia in 1925 to collect a sample of one of the rarest minerals, the Black Opal. Along the way, they meet a young girl with a secret that just may change their lives forever. As they search for the Black Opal, the kids must avoid stampeding kangaroo, flying boomerangs and survive a goat cart race at the Easter fair. When their escape plan lands them 2000 years into the future, will they be able to get back home? You can read the full book blurb here.

The Crystal Cave Adventure series has a self-contained story in each book with a story arc that carries through all of the books. As they solve one mystery, another mystery begins.

The Crystal Cave Adventure series is available in eBook and paperback at all major retailers. For a free introduction into the series, you can download a copy of Viktor’s Ice, the prequel novella which tells the story of the birth of the Crystal Cave. When Mr. M and his students discover the magical cave and fall hundreds of years into the past, can they survive being stranded in the Arctic Ocean with a longship full of Vikings? What mineral will they find that just might save the day? You can get a free copy at Mini Me Geology, the Author’s Website, or from Prolific Works (formerly Instafreebie).

The Crystal Cave Adventure series is written by a geologist, Tracy Barnhart, who loves all things geology, adventure and time travel! The series is published by Giverny Press.