| Coesite | |
|---|---|
 | |
| General | |
| Category | Tectosilicate, quartz group |
| Formula (repeating unit) | SiO2 |
| IMA symbol | Coe[1] |
| Strunz classification | 4.DA.35 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H–M symbol) |
| Space group | C2/c |
| Unit cell | a = 7.143 b = 12.383 c = 7.143 [Å] β = 120.00° Z = 16 |
| Identification | |
| Formula mass | 60.0843 g/mol |
| Color | Colorless |
| Crystal habit | Inclusions in UHP metamorphic minerals up to 3 mm in size |
| Fracture | Conchoidal |
| Tenacity | Brittle |
| Mohs scale hardness | 7.5-8 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent |
| Density | 2.92 (calculated) |
| Optical properties | Biaxial |
| Refractive index | nx = 1.594 ny = 1.595 nz = 1.599 |
| Birefringence | +0.006 |
| 2V angle | 60–70 |
| References | [2] |
Coesite (/ˈkoʊsaɪt/)[3] is a form (polymorph) of silicon dioxide (SiO2) that is formed when very high pressure (2–3 gigapascals), and moderately high temperature (700 °C, 1,300 °F), are applied to quartz. Coesite was first synthesized by Loring Coes, Jr., a chemist at the Norton Company, in 1953.[4][5]
- ^ Warr, L. N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C., eds. (1995). "Coesite" (PDF). Handbook of Mineralogy. Vol. 2 (Silica, Silicates). Chantilly, Virginia: Mineralogical Society of America. ISBN 0962209716. Retrieved December 5, 2011.
- ^ "coesite". Dictionary.com Unabridged (Online). n.d.
- ^ Coes, Jr., L. (31 July 1953). "A New Dense Crystalline Silica". Science. 118 (3057): 131–132. Bibcode:1953Sci...118..131C. doi:10.1126/science.118.3057.131. PMID 17835139. The word coesite is pronounced as "Coze-ite", after chemist Loring Coes, Jr.
- ^ Hazen, Robert M. (22 July 1999). The Diamond Makers. Cambridge University Press. p. 91. ISBN 978-0-521-65474-6. Retrieved 2012-06-06.