GEOLOGY 101 1st Edition Lecture 8 Outline of Last Lecture I. Mineral IdentificationII. Mineral GroupsIII. Hydrothermal FluidsOutline of Current Lecture I. GemsII. RocksCurrent LectureGems:- What makes a gem, a gem?o Beauty: How light reflects by luster and color.o Transparencyo Brilliance: Enhanced by cutting and polishing.o Durability: Based on hardness (harder than quartz)o Rarity or perceived rarity.- Diamonds:o Covalent bondso 10 on the hardness scaleo Polymorph of carbon along with graphiteo Formed in the mantleo Most are believed to be very old (most about 3 billion years old)o Brought to the surface through kimberlite pipeso Can be found as placer depositions (igneous rock)o Uses: gems, cutting and polishingo Diamonds only exist on the surface because they were brought up fast; if they were to equilibrate on the way to the surface, the stable form of carbon would be graphite.Rocks:- Rock Appearance:1) Mineralogy:2) Texture: size, shape, and arrangement of the minerals (coarse, fine, layered)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- 3 Major Rock Types:1) Igneous: formed by the solidification of molten rock or melt2) Sedimentary: formed by wither cementing together fragments of pre-existing rocks or by precipitation of mineral crystals our of water solutions at or near the earth surface.3) Metamorphic: formed when pre-existing rocks change character in the solid state as a response to a change in pressure and temperature conditions (does not require melting).The Rock
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