Rock & Mineral Questions |
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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 the three big groups of rocks?
What term is used for metamorphic rock with banded texture?
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 types of crystals are there?
What affects growth of crystals and how?
What items do metamorphic rock make up?
Are amethysts part of geodes or are the minerals in geodes different?
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?
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 is the strongest crystal?
How do I clean gems that I found while gem mining?
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 many directions of cleavage does calcite, which forms rhomb-shaped fragments, contain?
What particle gives rock texture?
Which of the following is the unit of weight used for measuring diamonds (about 0.2 grams)?
What determines the color/texture of a rock?
What element, when added to quartz, causes the purple color of amethyst?
What grains are in conglomerate rocks?
What type of minerals dissolves best in water?
Why do minerals have different characteristics?
Can a metamorphic rock mix up with a sedimentary rock? What would it form?
What kinds of rocks are similar to layers of cake?
How can I tell a rock is a cave rock?
Why do minerals rarely exhibit pure chemical composition?
I would like to know what to do with crystal like stones, you find around old rock sites or houses? Are they worth anything? Are there gold mines in Texas?
Why do sandstone rocks sometimes have holes in them?
Potassium Feldspar is most likely to form in?
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 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 |
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 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 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 |
Are amethysts part of geodes or are the minerals in geodes different?Geodes can contain amethyst crystals.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 |
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 is the strongest crystal?Diamonds are the hardest crystals with strong carbon bonds.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 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 |
What particle gives rock texture?A rocks texture is determined by the size and shape of all of its mineral grains.Back to Top |
How many directions of cleavage does calcite, which forms rhomb-shaped fragments, contain?Calcite has three (3) directions of cleavage.Back to Top |
What determines the color/texture of a rock?The color and texture of a rock is determined by the mineral content and its formation method.Back to Top |
Which of the following is the unit of weight used for measuring diamonds (about 0.2 grams)?Diamonds are measured in carats.Back to Top |
What grains are in conglomerate rocks?Conglomerate rocks are made up of many different types of grains from sand to various types of rocks.Back to Top |
What element, when added to quartz, causes the purple color of amethyst?Ferric Iron (Fe3+) is the element that causes the color purple in amethyst.Back to Top |
Why do minerals have different characteristics?Minerals have different characteristics because they are made of varying elements and have different crystal structures.Back to Top |
What type of minerals dissolves best in water?Calcite can often dissolve in water.Back to Top |
Can a metamorphic rock mix up with a sedimentary rock? What would it form?Sedimentary rocks are formed from pieces of other rocks and minerals. A metamorphic rock can become a sedimentary rock if the rock is broken apart through wind and flowing water and becomes sediment. The sediment can then be compacted or cemented into a sedimentary rock.Back to Top |
What kinds of rocks are similar to layers of cake?Sedimentary rocks are often formed in layers. Metamorphic rocks can also be layered; however, it is usually because the original rock was layered.Back to Top |
How can I tell a rock is a cave rock?Unless the rock you have was found in a cave setting it may be no possible to conclusively say that it is a cave rock. Caves often form in limestone rocks because they can be dissolved by running water.Back to Top |
Why do minerals rarely exhibit pure chemical composition?In order for a mineral to exhibit pure chemical composition, the right set of circumstances must be present. These circumstances include the right chemical elements and the right setting. Many factors are often present, such as available elements or poor location, that can alter the color or shape of a growing crystal.Back to Top |
I would like to know what to do with crystal like stones, you find around old rock sites or houses? Are they worth anything? Are there gold mines in Texas?If you find crystals or stones and are wondering what to do with them you can take them to a local geologist at a university or jewelry store for identification. These professionals can help you make an identification of the rock or mineral and tell you if the item is worth money or useful for other applications such as jewelry. I am unsure if there are active gold mines in Texas but you could check with the Texas office of the United States Geological Services for that information.Back to Top |
Why do sandstone rocks sometimes have holes in them?Sandstone rocks with holes are known as porous sandstones. The porosity is formed when spaces are left during the cementation process. The cementation process is when a liquid form of a mineral such as calcite or quartz “glues” the sand grains together. The holes that are left are great places for storing water or oil. Some sandstones have more holes than other depending on the amount of calcite or quartz that fills in between the sand grains.Back to Top |
Potassium Feldspar is most likely to form in?Microcline, sanidine, anorthoclase, and orthoclase are all potassium feldspars. Feldspars are some of the most common minerals on Earth most often occurring in igneous rocks although some feldspars are found in metamorphic rocks. Some notable occurrences of potassium feldspars are in the Pikes Peak region of Colorado, North Carolina, among other sites in the northeastern portion of the USA; Salzburg, Austria; Cornwall, England; Russia; Norway; Italy; and Madagascar and others.Back to Top |