Ask A GeologistDo you have questions about geology, rocks and minerals and you can’t find the answers? Then ask a geologist! We have an extensive list of questions so far so browse through and see if your question is already answered. If you don't see what you're looking for, click here to ask your own question. Then check back later to see if your question and answer has been added to our site. Please include the age of the child when submitting so we can answer the question appropriately for their age group. |
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How could mineral hardness be used to tell quartzite from marble?
What is obsidian rock used for?
Name four kinds of igneous rocks.
What are some household items made out of igneous rock?
What are the three big groups of rocks?
In what parts of the world can sandstone rock be found and what are some of its uses?
What term is used for metamorphic rock with banded texture?
What rocks are changed by high pressure and high temperature?
What is in magma that makes up a rock?
When you find rocks, what type of notes should you take about them?
What would be some advice for a neophyte trying to find rocks?
What happens to rock fragments that get buried after a long time?
Why are some metamorphic rocks hard to identify?
Why do you think some sandstones are harder than others?
Why do scientists check rocks to see if they have calcite?
What is one thing you can do to figure out what kind of rock you have?
What types of crystals are there?
What affects growth of crystals and how?
What items do metamorphic rock make up?
What sort of things do you have to do when you're a geologist and is it fun?
What test do geologists use to tell hardness?
Are amethysts part of geodes or are the minerals in geodes different?
After four years of college how can you become a geologist?
What two groups of rocks are formed from all three kinds of rocks?
What class of sedimentary rocks is made of fragments of rocks, minerals, and shells?
What is the name of sand grains cemented together?
Where is the mineral feldspar located in the United States?
Where is siltstone on Mohs hardness scale?
What are wavy features found on some sandstones?
What is the term for the layering of sedimentary rock?
At school we had to choose a career and give a presentation. What kind of props would I need to show them about geology?
How do different rocks form?
Where does graphite come from?
What is inside a rock?
Can you cut a rock in half?
What are gems and crystals used for?
Can rocks be different colors?
Can a metamorphic rock become big?
Were do gems come from?
How do minerals form?
Which rocks have the name that means fire?
What are the remains of once living organisms found in sedimentary rocks?
What is the strongest crystal?
How many years of college do you have to attend to become a geologist?
What is the liquid portion of a volcano called and what is the name for the bits of rock and ash?
How do I clean gems that I found while gem mining?
What is the largest igneous intrusion in California ? What kind of rock is it? And where is it found?
How do bits of broken rock become sand?
What are the hollow ball-like objects, such as quartz, which are found in sedimentary rocks?
What is the strongest sedimentary rock, and which is the weakest?
How could mineral hardness be used to tell quartzite from marble?I don't know that hardness would be a good test since both of these rockshave undergone metamorphism. In theory, quartzite should be harder because it is made of Quartz which has a hardness of 7 on the Mohs scale and Marble is made of calcite which is has a hardness of 3 on Mohs scale. The best test is the "fizz test." If you drop a dilute acid on the rocks, the marble will bubble or fizz. You can use vinegar since it is a very weak acid and see if you can observe the fizz. Anything made of calcite should fizz but quartz will not. Back to Top  |
What is obsidian rock used for?In ancient times, obsidian was used to made crude knives and tools. Today, obsidian is used in the production of rock wool, knives and jewelry.Back to Top |
Name four kinds of igneous rocks.You can look through the “Igneous Rocks” link on the left side of our website and find the ones you like best!Back to Top |
What are some household items made out of igneous rock?Many building materials are made of granite such as counter tops in homes. Pumice is also used in products such pumice stones which are used to smooth rough feet and in Lava Soap which is used to remove grease from hands.Back to Top |
What are the three big groups of rocks?The three basic rock types are Igneous, Metamorphic and Sedimentary. See the article titled Geology is All Around You in the “Dig Into Geology” section of our website for more information on these rock types.Back to Top |
In what parts of the world can sandstone rock be found and what are some of its uses?Sandstones can be found at worldwide locations. They are often used as building materials and in industrial processing applications (e.g. grind stones). A natural use of sandstone is as a reservoir for water, oil and gas. The spaces between sand grains can be either open or filled. If the spaces are open, sandstones make good places for water, gas and oil to be stored below the land surface.Back to Top |
What term is used for metamorphic rock with banded texture?You may be referring to “foliation” which is the layering within a metamorphic rock. Foliation occurs when there is a strong pressure applied to the rock in one direction, just like when you put your hands flat together and push. When this pressure is applied, certain minerals, like mica and chlorite, grow with their long direction perpendicular to the pressure. This make the rock appear with layering and/or banding.Back to Top |
What rocks are changed by high pressure and high temperature?The change of a rock by high temperature and pressure is called metamorphism. This is the process by which metamorphic rocks are formed. Any rock can be changed by metamorphic processes.Back to Top |
What is in magma that makes up a rock?Magma is the term used for liquid rock which forms deep below the Earth’s surface. Magma can be composed of many different things such as silicates, alkalis, iron and magnesium. The composition of the magma will determine the type of rocks which it will eventually form.Back to Top |
When you find rocks, what type of notes should you take about them?I like to write down anything you can see – color, texture, possible mineral content, size of minerals, and location of rock. I even like to draw a picture of it and possibly a drawing of how it was oriented when you found it. All of this can be great information to remember when you get home. Back to Top |
What would be some advice for a neophyte trying to find rocks?The best thing to do is to start looking around your home for rocks. Have your parents take you on nature walks where you can look for rocks and minerals.Back to Top |
What happens to rock fragments that get buried after a long time?These rock fragments will be heated and compressed and either combine into a new rock or be metamorphosed into a new rock.Back to Top |
Why are some metamorphic rocks hard to identify?The high temperatures and pressured which occur during the metamorphism can destroy some of the characteristics of the original rock which can make identification tricky.Back to Top |
Why do you think some sandstones are harder than others?The minerals that are used to cement the sand grains together can vary. If quartz is used the rock will likely be harder than if calcite is used.Back to Top |
Why do scientists check rocks to see if they have calcite?Calcite can be a good indicator mineral for determining the type of rock and the how it was formed.Back to Top |
What is one thing you can do to figure out what kind of rock you have?The type of rock is based on the minerals present and the method used to form the rock. If you are trying to identify a rock sample, looking for the various minerals and comparing them to a known sample or picture can be helpful.Back to Top |
What types of crystals are there?There are many types of crystals in the world. Some of the most common are quartz, calcite and halite.Back to Top |
What affects growth of crystals and how?Many things can affect the growth of a crystal such as amount of solution available, location, space, temperature, and pressure.Back to Top |
What items do metamorphic rock make up?I assume based on the search you did that you are trying to determine what type of common household items may be made from metamorphic rocks. Mostly, they are used for building materials such as floors, roofs, walls, bathroom surfaces, etc. Marble and slate are two of the most common building materials. Gneiss (pronounced "nice") and quartzite also used for building materials sometimes. Some metamorphic rocks, like garnet schist, are mined for their mineral content. The minerals can be used for a variety of uses, like jewelry.Back to Top |
What sort of things do you have to do when you're a geologist and is it fun?The types of activities you do as a geologist vary depending on the field in which you work. Some geologists work for oil companies and they find oil and gas reserved underground, others work for environmental firms who help industries meet laws that are designed to protect the earth’s natural resources and cleanup and spills that occur. Geologists can also be employed by the United States Environmental Protection Agency, state regulatory agencies, the United States Geological Survey and Universities. Geology can be very fun if you find the job that fits the types of activities that you like to do. Geologists can work outside or in an office, they can manage other people or even run the business. Anything can be fun it you do what you love!Back to Top |
What test do geologists use to tell hardness?Check out this article on our Dig into Science pages on how to use the mineral hardness test.Back to Top |
Are amethysts part of geodes or are the minerals in geodes different?Geodes can contain amethyst crystals.Back to Top |
After four years of college how can you become a geologist?You can get your degree in Geology in four years from many Colleges and Universities. You can be hired with the title of Geologist with this degree. Most states also offer the ability to get Professional Geologist license. Each state is different but generally you have to work for a several years and take a test to earn the professional license.Back to Top |
What two groups of rocks are formed from all three kinds of rocks?Sedimentary and metamorphic. Check out our Dig into Science pages for more information on the types of rocks.Back to Top |
What class of sedimentary rocks is made of fragments of rocks, minerals, and shells?Detrital sedimentary rocks. Examples of these types of rocks are shale, sandstone and breccia.Back to Top |
What is the name of sand grains cemented together?Sandstone is the rocks which consists of sand grains that are cemented together.Back to Top |
Where is the mineral feldspar located in the United States?Feldspar minerals are one of the most common rock forming minerals and can be found in many locations in the United States.Back to Top |
Where is siltstone on Mohs hardness scale?Siltstone is a rock. Mohs hardness scale measures the hardness of minerals. The hardness of the siltstone would be determined by the hardness of the individual minerals making up that siltstone.Back to Top |
What are wavy features found on some sandstones?Ripple marks. These are features that show that a sandstone was formed in an area with wave motion in the sea.Back to Top |
What is the term for the layering of sedimentary rock?Often these rocks are just called layered. Sometimes people use the term “banded” when referring to layered rocks with distinct color or mineral changes.Back to Top |
At school we had to choose a career and give a presentation. What kind of props would I need to show them about geology?A geologist can use different types of equipment depending upon their job functions. Field geologists often use a rock hammer, field book, Brunton compass, and a hand lens for studying and mapping rocks in the field. In the office, geologist use computers, models, maps and analytical equipment to analyze the data that is collected in the field.Back to Top |
How do different rocks form?Check out our Dig Into Science page article on rocks and minerals for information.Back to Top |
Where does graphite come from?Graphite is a native mineral made of carbon. China, India and Brazil tend to produce the most graphite from mines.Back to Top |
What is inside a rock?Most rocks consist of the same minerals within the rock that you see on the outside. Often, rocks appear dull on the outside because of exposure to wind and rain. Often, if you break a rock open you can better see the minerals and their characteristics.Back to Top |
Can you cut a rock in half?Yes, you can break a rock using a rock hammer or use a rock saw. Always get your parents or a teachers help before doing this and make sure to wear safety glasses.Back to Top |
What are gems and crystals used for?Minerals have many different uses which range from dyes, fertilizers, building materials, to jewelry among others. For more information, check out this link for a Dig Into Science article on rocks and minerals.Back to Top |
Can rocks be different colors?Yes. The color of a rock is determined by the colors of the minerals which make up the rock. Rocks with dark minerals appear dark or black. Rocks with light colored minerals will appear light in color.Back to Top |
Can a metamorphic rock become big?Yes. Regional Metamorphism, which is the term used when large areas of rock are metamorphosed at the same time, will cause very large metamorphic rocks.Back to Top |
Were do gems come from?Minerals can be found at many locations around the globe. The quality of the mineral specimen determines if the minerals are gem-quality.Back to Top |
How do minerals form?The most common methods are for minerals to form from the cooling of a liquid like molten lava from a volcano, hot liquids in caves or cracks, or from evaporation of a lake or sea.Back to Top |
Which rocks have the name that means fire?Pyrite. This mineral’s name means ‘fire’ in Greek.Back to Top |
What are the remains of once living organisms found in sedimentary rocks?Fossils are the remains or impressions of once living organisms that are often found in sedimentary rocks.Back to Top |
What is the strongest crystal?Diamonds are the hardest crystals with strong carbon bonds.Back to Top |
How many years of college do you have to attend to become a geologist?You can earn a Bachelor of Science geology degree in four (4) years from a university. You can also get a Master of Science and PhD with additional years in graduate school.Back to Top |
What is the liquid portion of a volcano called and what is the name for the bits of rock and ash?Magma is the liquid portion of volcano. The magma is liquid rock. Volcanic ash is expelled from the volcano when it erupts. Volcanic ash is made of small bits of rock and ash.Back to Top |
How do I clean gems that I found while gem mining?To clean your samples start with a fine brush and gently brush soil and debris from the rock or mineral. Some rocks can be damaged by brushing too hard. You can use cold water to clean your specimens but be careful since some minerals dissolve in water. Also, never use hot water since the hot water can cause some minerals to crack or break.Back to Top |
How do bits of broken rock become sand?Bits of broken rock can be weathered (changed) into sand by wind and water breaking down the rock bits.Back to Top |
What is the largest igneous intrusion in California ? What kind of rock is it? And where is it found?Batholiths are typically the largest igneous intrusions. One example of a large batholith is Big Rock near Riverside, California. Big Rock is a part of a batholith which is composed of mostly granite with some inclusions of gabbro.Back to Top |
What is the strongest sedimentary rock, and which is the weakest?The strength of a rock varies based on its formation. However, an example of a strong sedimentary rock would be sandstone and an example of a weak sedimentary rock would be loess.Back to Top |
What are the hollow ball-like objects, such as quartz, which are found in sedimentary rocks?By “hollow ball-like objects” I believe you are thinking of geodes. Geodes are round in shape and hollow in the center. Geodes are usually filled with crystals such as quartz and amethyst.Back to Top |