GEOL 101 1nd Edition Lecture 5 Outline of Last Lecture I. Dynamic EarthII. Minerals as Building BlocksIII. Physical Properties of MineralsOutline of Current Lecture I. Classification of MineralsII. Classification of Silicate MineralsIII. Classification of Non-silicatesIV. Mineral Resources Current Lecture-Rock-Forming of Minerals- These are common minerals that make up almost all of the Earth’s crust.- There are only a few dozen members. - It is only composed of 8 elements on the Periodic Table that make up about 98% of the crust.- Out of the 4000 minerals discovered, the remaining 3900 are rare with less common elements. *Oxygen (in solid form) is the primary abundance in the crust.*-Classification of Minerals (Common Groups)- Silicates: Silicon + Oxygeno Ex: Quartz (SiO3)- Oxides: Metal + Oxygeno Ex: Hematite (Fe2O3)- Carbohydrates: Contains CO3 ionso Ex: Calcite (CaCo3)- Sulfides: Metal + SulfurThese 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.o Ex: Pyrite (FeS2)- Native Elements: Pure elementso Ex: Sulfur, Gold-Silicates- Most important mineral groupo Comprise most of the rock-forming mineralso Very abundant because of the large amounts of Si and O in crust- Silicon-Oxygen Tetrahedron molecule (basic building block)o Four Oxygen ions surrounding smaller Silicon ion. -Silicate Structures- Basic building blocks of Silicate come and connect together to form a lot of structures that include:o Isolated Tetrahedra Olivine- High temperature- Individual tetrahedral linked by iron and magnesium- Forms small, round crystals without cleavageo Ring Structureso Single Chained Proxene- Involve Iron and Magnesium- Two distinct cleavages at 90 degrees- Augite is most commono Double Chained Amphibole Group-Complex Fe-Mg silicates- Have variety of ions- Two perfect cleavages with 124 and 56 degree angles- Hornblende is most common mineralo Sheet or Layered Structures Mica Group-Complex Silicate- Have one direction of perfect cleavage- Peel off layerso Complex 3D Structures Feldspar Group- Most common mineral group- 3D framework that have two directions of perfect cleavage at 90 degrees- Orthoclase and Plagioclase are most common Quartz- Only common mineral with just Si and O- Exhibits conchoidal fracture- Resistant to erosion- Clay Mineralso Clay is general term used to describe complex mineralso All have layered and sheet structureso Make up large percentage of soils-Classification of Non-Silicates- Important mineralso Oxides Not volumetrically abundant but are locally concentrated to make metal oreso Carbohydrates Calcite and Dolomite are two most important Most caves form in limestone, a rock primarily made up of Calciteo Sulfides Can be important ores for metals, but can form sulfuric acido Native Elements Made up of only one element Most are rareo Sulfateso Halideso Phosphates-Mineral Resources- Is a loose term for the natural solid material we use for profit- Ore Deposits-mineral deposits that are high enough to concentration that become economically viable o Depends on economy. Depends if the money for the mineral is worth the money to spend getting
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