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Warm-up for Monday, 3/21/16 Title your paper Warm-ups for 3/21 – 3/24/16. 1. Below earth’s surface are areas of melted rock called ______. When magma ______ and _______, ________ rocks form. 2. A ___________ rock is a rock that is formed from other rocks by extreme _______and ________. cooled quickly cooled slowly 3. _________ rocks are formed from sediments that are __________ and _________ together. Directions: Write the sentence and fill in the blank.
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Warm-up for Monday, 3/21/16 Title your paper Warm-ups for 3/21 – 3/24/16. 1. Below earth’s surface are areas of melted rock called magma. When magma cools and hardens, igneous rocks form. 2. A metamorphic rock is a rock that is formed from other rocks by extreme heat and pressure. cooled quickly cooled slowly 3. Sedimentary rocks are formed from sediments that are compacted and cemented together.
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What is a rock? A rock is a naturally occurring solid substance that is normally made of minerals. Some rocks are made of only one mineral. Others are made of several minerals combined. By figuring out what minerals are in a rock and understanding how they are formed geologists place rocks into one of three groups: Igneous metamorphicsedimentary and.
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Igneous Rocks Below earth’s surface are areas of melted rock called magma. When magma cools and hardens, igneous rocks form. Igneous rocks can also form from lava above earth’s crust. The texture of an igneous rock depends on how fast the magma cools to form the rock. The slower it takes to cool the more mineral grains will form. If it cools quickly, the rock will have a smoother, glassy texture. obsidian basalt granite
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Sedimentary Rocks Sedimentary rocks are formed from sediments that are pressed and cemented together. These layers are made of tiny pieces called sediments. Some sediments are formed from rocks or minerals. Others are bits of plants, shells, or other hard materials. It can take millions of years for sediments to become rocks!
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metamorphic Rocks A metamorphic rock is a rock that is formed from other rocks by extreme heat and pressure. When rocks are under extreme heat or pressure (like under earth’s surface!) their physical appearance can change. granite gneiss
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The Rock Cycle
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What is a mineral? Minerals are the building blocks of rocks. Scientists have discovered over 3,000 types of minerals! A mineral is a natural, nonliving substance. Minerals must occur naturally and are non-living. Minerals can be elements or compounds. They are pure substances with a chemical formula. Minerals have a crystalline structure. Rocks are mixtures of minerals and other materials.
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How do we identify minerals? We observe the physical pr operties of minerals.
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Minerals are identified by their physical properties: hardness crystal shape (form) luster color streak cleavage/fracture density (specific gravity) special properties –reaction to acid –fluorescence –salty taste –magnetism
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But don’t worry…we’re only going to focus on FIVE! Hardness (scratch test) Luster Color Streak Density
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Physical Properties of Minerals Color: Color alone, cannot identify minerals. Many minerals have the same color. Quartz can be many different colors! Hardness: refers to a minerals ability to scratch another mineral or be scratched (scratch test). The MOHS’ Scale shows the hardness of some common minerals. Each mineral has a number one - ten. Ten is the hardest kind.
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Luster : refers to the way light bounces off the surface of a mineral. Main categories are metallic (shiny luster) and nonmetallic which can be described as dull, waxy, pearly, glassy, and others. Streak : If you scratch a mineral along a white tile, it leaves behind a powder. A minerals streak is the color of that powder. The streak may be different from the color of a mineral’s surface! The color of the streak is a minerals true color.
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Properties of minerals mineralmicafeldspar hematite pyrite color white, green, silver, or brown white, pink, gray, or smoky black gray or brown gold or brassy yellow luster pearlydull or glassy metallic or dull metallic streak white redgreen-black hardness 2 - 2.56-6.5 5-6
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