mineral Calcite brittani wang 1

mineral Calcite is a magic mineral, is has an optical property called birefringence, which means double refraction. birefringen ce 2

mineral It could be colorless, white, grey, yellow, green, red, brown or even black for its impurities. It also could fluoresced red, blue, yellow and other colors under either SW and LW UV. colorful 3

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Mineral properties mineral Category: Carbonate mineral Luster: vitreous to pearly Formula: CaCO3 Steak: white. Crystal habit: crystalline, granular, stalactites, concretionary, massive, Diaphaneity: Transparent to translucent Cleavage: Perfect on three directions Specific gravity: 2.71 Fracture: Conchoidal Optical properties: Uniaxial Tenacity: brittle Solubility: Soluble in dilute acids Mohs scale hardness:3 Crystal system: Trigonal hexagonal scalenohedral 5

mineral Crystal system 6

mineral Formation processes Calcite forms a precursor( amorphous calcium carbonate) Two ways: ACC nanoparticles rapidly dehydrate and crystallize to form individuals particles of vaterite The vaterite transforms to calcite via a dissolution and reprecipitation mechanism with the reaction rate controlled by the surface area of calcite. 7

mineral We need to know Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate(CaCO3). Calcite has a defining Mohs hardness of 3. 8

We need to know mineral Calcite’s luster is vitreous and pearly on cleavage surfaces. Cleavage is always in three directions parallel to the rhombohedron form Calcite’s fracture is conchoidal but its rare exist naturally. 9

We need to know Calcite don’t have magnetism and no effervescence. mineral Calcite don’t have magnetism and no effervescence. The streak of calcite is white Calcite is transparent(Iceland spar) to opaque and may show phosphorescence 10

mineral We need to know Calcite is a carbonate mineral, it can dissolve with most forms of acid. Temperature, PH and ion concentrations in the water can effect its rate of dissolve. Calcite also has a unusual characteristic, retrograde solubility which can gather rocks together to fill the fractures. 11

Common uses of the mineral 12

mineral High- grade optical It was used in World War 2 for gun sights, specifically in bomb sights and anti-aircraft weaponry 13

mineral Microbiologically precipitated calcite has a wide range of applications, such as soil remediation, soil stabilization and concrete repair 14

mineral Natural occurrence 15

mineral limesto ne Calcite is a common constituent of sedimentary rocks. It’s formed from the shells of dead marine organisms. 16

mineral Bibliography:http://photo.baike.com/photo_100002010102300461483 http://bbs.geonet.cn/thread-48553-1-1.html http://www.numac.com.au/environmental-services.html http://www.minsocam.org/ammin/AM66/AM66_885.pdf】 Thanks for watching 17