Geology

A:

Metamorphic rocks are most often found in mountainous regions though they can be seen wherever there are signs of geological upheaval in an area. This type of rock is formed by the transformation of another rock type, a change that is usually triggered by tremendous heat, pressure or other violent phenomena. The forces that cause metamorphic rocks to form are so great that they change not only the appearance but also the chemical composition of an existing rock.

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  • Where do rocks come from?

    Q: Where do rocks come from?

    A: Rocks come from magma, which is the molten material found within the earth. When magma cools, either above or below the earth's surface, it crystallizes and forms the igneous rocks that can later be changed into metamorphic or sedimentary rocks. Magma, which can be considered molten rock, is referred to as lava when it reaches the earth's surface.
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  • What rock is formed when magma cools at the Earth's surface?

    Q: What rock is formed when magma cools at the Earth's surface?

    A: The specific type of rock that forms when magma cools at the Earth's surface is extrusive igneous rock. Igneous rock forms when magma cools, but where the magma cools determines the type of igneous rock that forms. Igneous rock gets its name from the Greek word for fire and is so called due to the extremely hot liquid from which the rocks originate.
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  • Why is limestone important?

    Q: Why is limestone important?

    A: According to the U.S. General Services Administration, limestone is important because it is widely used in architectural applications for walls, decorative trim and veneer. It is less commonly used in making sculptures because of its porosity and softness.
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  • How do you turn copper green?

    Q: How do you turn copper green?

    A: To turn copper green, create a verdigris paina by rubbing the metal with a vinegar and salt solution. Before you begin, gather some steel wool, a bowl, paper towels, dish soap, baking soda and a finishing wax or lacquer.
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  • What are the four processes that result in the formation of minerals?

    Q: What are the four processes that result in the formation of minerals?

    A: Minerals are formed by organic processes, crystallization, melting and crystallographic transformations that occur in the mineral's solid state. Crystallographic transformations generally occur with a change in the pressure or temperature in the material surrounding the mineral deposit.
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  • What is the difference between soil and sand?

    Q: What is the difference between soil and sand?

    A: Soil is made up of liquids, solids and gases that form on the surface of land, while sand is a natural material that consists of at least 85 percent sand-sized particles. Soil consists mostly of organic matter, such as decomposing animals and plants and minerals. The most common sand found throughout the world is made up of quartz, or silicon dioxide.
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  • How do fossil fuels form?

    Q: How do fossil fuels form?

    A: Fossil fuels are formed the gradual accumulation of organic remains on the sea floor. As the accumulation rate increases, the organic remains are subjected to heat and pressure, which leads to fossil-fuel formation.
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  • How is shale formed?

    Q: How is shale formed?

    A: Shale forms from the pressure of layers of sediment compressing bits of silt that settle into the clay on the bottom of bodies of water. The compressed clay and silt become shale over time. Shale is a sedimentary rock.
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  • What is sedimentary rock?

    Q: What is sedimentary rock?

    A: Sedimentary rocks are formed by the deposition of mud, clay, sand and other small particles on the surface of the Earth. Sedimentation can occur in many different environments, including lakes, rivers, deserts and oceans. The sediment is deposited in layers that are compressed over time and turned into solid rock.
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  • What is absolute dating?

    Q: What is absolute dating?

    A: Absolute dating is a method of determining the specific date of a paleontological or archaeological artifact or location based on a specific time scale or calendar. Scientists base absolute dating on measurable physical or chemical changes or on written records of events.
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  • What is the texture of granite?

    Q: What is the texture of granite?

    A: Granite has a coarse to very coarse grained texture. It is typically granular and can be porphyritic with well-shaped large crystals of feldspar. Its structure contains cavities wherein well-formed crystals project.
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  • How much is topaz worth?

    Q: How much is topaz worth?

    A: The market value of topaz varies greatly, ranging from approximately $8 to $749 per carat as of September 2014. Its worth is determined by a number of factors such as weight, color, clarity, cut and shape. A gemologist must appraise the gem to provide an exact estimate.
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  • How do petrified fossils form?

    Q: How do petrified fossils form?

    A: According to the Oxford University Museum of Natural History, petrified fossils form when mineral deposits replace the bones of dead creatures inside hardened sediment. Over time, these deposits completely replace the remains, forming an image of the bones out of solid rock.
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  • How can you tell if something is real silver?

    Q: How can you tell if something is real silver?

    A: Real silver is identified by its sound, its lack of magnetic qualities and by its ability to conduct heat. For instance, when tapped together, two silver coins emit a high, clear tone. The bell-like ring continues for a second or two.
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  • What is the hardest mineral in the world?

    Q: What is the hardest mineral in the world?

    A: The hardest natural mineral in the world is lonsdaleite, a rare mineral made of carbon atoms. This mineral can withstand up to 58 percent more stress than diamond, according to a report by Jessica Griggs of NewScientist.
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  • What is a mine-cut diamond?

    Q: What is a mine-cut diamond?

    A: Mine-cut diamonds are typically square or slightly oval and have a deeper crown and pavilion, or top and bottom, than modern stones. "Mine cut" does not refer to the place the diamond was faceted, but rather to its overall shape and brilliance.
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  • What are metamorphic rocks used for?

    Q: What are metamorphic rocks used for?

    A: Metamorphic rocks are used for roofing material, decorative gardening stone, the base for snooker tables, building material, sculpture material and paving material. Metamorphic rocks come in three different types: slate, marble and schist.
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  • Where can you find geodes?

    Q: Where can you find geodes?

    A: Geodes are mostly found in deserts, volcanic ash beds and areas with limestone throughout the world. In the United States, common geode sites include Arizona, California, Iowa, Nevada and Utah. The most abundant geode sites in California are Riverside and Imperial counties.
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  • How is sandstone formed?

    Q: How is sandstone formed?

    A: Sandstone forms over the course of centuries, as deposits of sand accumulate in rivers, lakes or on the ocean floor, and the sand blends with calcite or quarts and then undergoes compression. After enough time goes by, the pressure pushes all of these elements together to create sandstone. Because not all sand is identical but instead comes in a variety of colors and grain textures, each formation has a unique appearance.
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  • What is dry lava called?

    Q: What is dry lava called?

    A: Dry lava is called igneous rock. The superheated molten rock that reaches the surface in an eruption is called lava, and lava may flow for miles before cooling.
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  • How do you tell if something is real crystal?

    Q: How do you tell if something is real crystal?

    A: While it's often necessary for an expert to examine the item, crystal can be distinguished by its ability to cast rainbow colors when held up to the light. Real crystal also contains lead, so it is heavier than glass and reverberates a distinct ringing sound when struck.
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