Mineral and Gemstone Properties Table

In this section a table containing the description of the most common minerals and gemstones (ca. 400 species among the 3700 mineral species known today) is presented with their 

Mineral name (IMA) (CAS RN) (Synonyms) (Etymology) (ICSD and PDF diffraction files numbers) Theoretical chemical formula, relative molecular mass ( C = 12), mass percentages, coordinence number, major impurities, Strunz s mineral class Crystal system, lattice parameters, Strukturbericht, Pearson symbol, (Z), point group, space group, structure type Optical properties s II fe C) 3. Other relevant mineralogical, physical, and chemical properties with occurrence 

Agate (syn., chalcedony) [Named after the River Achates, now Drillo in Sicily, where it was originally found] SiO, M s 60.0843 46.74 wt.% Si 53.26 wt.%0 Coordinence Si(4) (Oxides, and hydroxides) Amorphous Isotropic 6 2600 Mixture of cryptocrystalline and amorphous silica consisting mainly of chalcedony. 

Alunite (Named from French alun itself from Latin, alumen, meaning alum] KA1,(SO,),(OH). M = 414.214334 9.44 wt.% K Trigonal (Rhombohedral) a= 697 pm Uniaxial ( ) s= 1.592 (0= 1.572 3.5-4 2600- 2900 Habit rhombohedral. Color white, gray. Streak white, gray. Diaphaneity transparent to translucent. Luster vitreous. FractureconchoidaL Qeavage good (001), poor (lOI). 

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Andalusite, kyanite, and sillimanite are three polymorphs minerals that belong to the ne-sosilicate minerals. Hence they have the same chemical formula [Al SiOj = Al Oj-SiOJ and all contain theoretically 62.92 wt.% Al O, and 37.08 wt.% SiO. They are distinguished from one another by their occurrence and physical and optical properties (see Section 12.7, Minerals and Gemstones Properties Table). Kyanite is easily distinguished from sillimanite or andalusite by its tabular, long-bladed, or acicular habit and by its bluish color and slightly lower hardness than sillimanite and andalusite. 

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