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Coesite [abbr. Coe ]

• SiO₂
• [Si⁴⁺][O₂]^4-

• Class: Tectosilicate
• Class: Oxide
• Phase transition: Formed on transition of heated Quartz at 2.0-10 GPa and above 500 degree.
• Phase transition: Transit to Stishovite above 10 GPa and above 573 degree.
• Stable at 500-800 degree, 2.0-10 GPa.

• Polymorph: Quartz (α) (<573 degree, Trigonal)
• Polymorph: β-Quartz (573-870 degree, Hexagonal)
• Polymorph: Tridymite (870-1470 degree, Triclinic)
• Polymorph: Cristobalite (>1470 degree, Tetragonal)
• Polymorph: Stishovite (>10 GPa, 500-800 degree, Tetragonal)
• Polymorph: Mogánite (Moganite) (Monoclinic)

• Si => Ge: Argutite
• Si => Sn: Cassiterite
• Si => Ti: Rutile, Anatase, Brookite
• Si => Pb: Scrutinyite (α), Plattnerite
• Si => Mn: Pyrolusite (β), Ramsdellite (γ), Akhtenskite (ε)
• Si => V: Paramontroseite
• Si => Mo: Tugarinovite
• Si => U: Uraninite
• Si => Th: Thorianite
• Si => Ce: Cerianite-(Ce)
• Si => Se: Downeyite
• Si => Zr: Baddeleyite
• Si => Te: Tellurite, Paratellurite

• Color: Colorless
• Streak: White
• Luster: Vitreous
• Diaphaneity: Transparent

• Cleavage: No
• Hardness: 7.5-8
• Density: 2.9

• System: Monoclinic
• Group: 2/m, C2/c
• Lattice: a=7.1, b=12.4, c=7.1, β=120.0