<p>Unit 2 – Rocks and Minerals Notes</p><p>Minerals are naturally occurring, inorganic, solids, with a crystalline structure, and definite composition, that cannot be broken into smaller substances.</p><p>Rocks are a mixture of minerals.</p><p>Physical properties can be observed or measured without changing the composition of matter. </p><p>Physical properties are used to observe and describe matter.</p><p>Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, and many others.</p><p>True color of the mineral samples is occasionally hidden by tarnish, rust, corrosion, or even soil. Some minerals might be found in a wide variety of colors.</p><p>Luster is the way light reflects from a mineral. Luster can be described as metallic, glassy, pearly, dull, and sparkling.</p><p>The resistance of a mineral to being scratched is known as hardness. Mohs Hardness Scale uses common objects (fingernail, penny, nail, glass) of a known hardness to scratch the minerals and rank its hardness from 1 to 10. 1 is the softest (talc) 10 is the hardest (diamond).</p><p>Streak is one of the most reliable properties used in identifying minerals. Streak refers to the color of the powder a mineral leaves after rubbing it on an unglazed porcelain streak plate. Note that this is not always the same color as the original mineral.</p><p>Specific gravity is the comparison of the mineral’s density to the density of water (1g/mL). Rock Cycle Vocabulary  Deposition – the natural process of adding transported sediments to a landform.  Erosion – the transport of fragments of rock by water, wind, ice, or gravity.  Extrusive igneous rock – rock formed from the cooling of molten rock on Earth’s surface.  Intrusive igneous rock – rock formed from the cooling of molten rock below Earth’s surface.  Lava – molten rock that has erupted onto Earth’s surface.  Lithification – the compaction and cementing of sediment into rock.  Magma – molten rock below Earth’s surface.  Metamorphic rock – rock that has been changed by heat and pressure.  Rock cycle – a continuous series of events through which a rock is transformed from one type to another.  Sediment – rock fragments that have been transported to a different location.  Sedimentary rock – rock formed from sediments, organic remains, or chemical precipitates.  Soil – the top layer of Earth’s surface that supports plant growth.  Weathering – the breakdown of rock due to rain, wind, ice, sunlight, and plants.</p>