EPSC 201 Lecture Notes - Lecture 11: Fluorite, Strategic Arms Limitation Talks, Calcite
26 Jan 2017
School
Department
Course
Professor
Document Summary
Made of oxygen and silicon with other atoms. Tetrahedron: four o atoms are bonded to a central si atom, define the corners of a four-sided geometric figure, the silica tetrahedron is the building block of silicates. Sheet silicates: silica tetrahedra share 3 o, create 2d flat sheets of linked tetrahedra, characterized by one direction of a perfect cleavage, example. Framework silicates: all four o in each silica tetrahedron are shared, examples. Silica (quartz) group contains only si and o. Gemstones a mineral with special value: rare formed by unusual geological processes, beautiful strikingly unique color, clarity and luster. Gem a cut and polished stone created for jewelry: precious stones that are particularly rare and expensive. Gems are cut and polished stones in jewelry: facets are ground onto a gem by a lapidary machine, faceting a gemstone takes a lot of time and effort, facets are not natural crystal faces.
