Reidite
| Reidite | |
|---|---|
| General | |
| Category | Zircon group |
| Formula (repeating unit) | ZrSiO4 |
| Strunz classification | 9.AD.45 |
| Crystal system | Tetragonal |
| Crystal class |
Dipyramidal (4/m) H-M symbol: (4/m) |
| Space group | I41/a |
| Unit cell | a = 4.738, c = 10.506 [Å], Z = 4 |
| Identification | |
| Formula mass | 183.31 g/mol |
| Color | Colorless to white |
| Crystal habit |
Epitaxial - crystallographic alignment with a precursor mineral, occurs as inclusions in other minerals. |
| Cleavage | None |
| Fracture | Irregular/uneven |
| Tenacity | Brittle |
| Mohs scale hardness | 7.5 |
| Luster | Adamantine |
| Streak | White |
| Diaphaneity | Translucent |
| Specific gravity | 5.16 |
| Optical properties | Uniaxial (+) |
| Refractive index | nω=1.64, nε=1.655 |
| Birefringence | 0.0150 |
| Pleochroism | None |
| References | [1][2] |
Reidite is a rare mineral that has been found only in four crater impacts: the Chesapeake Bay Crater in Virginia, Ries Crater in Germany, Xiuyan Crater in China, and Rock Elm Crater in Wisconsin in the United States.[3]
In 2015 an occurrence of reidite was reported from the Precambrian Stac Fada Member structure in North West Scotland, confirming its impact origin.[4]
Name origin
Reidite is named after the scientist who first created the high pressure phase in the laboratory in 1969, Alan F. Reid.
Formation
Zircon morphs into reidite when shock waves from meteorite impacts hike up pressures and temperatures to extreme levels, equal to those deep inside the Earth where diamonds form. The pressure makes minerals tightly repack their molecules into denser crystal structures. Reidite has the same composition as regular zircon but is about 10 percent denser.[3]
Related silica minerals
| 9.AD.25 | Uvarovite | Ca3Cr2(SiO4)3 |
| 9.AD.25 | Wadalite | (Ca,Mg)6(Al,Fe3+)4((Si,Al)O4)3O4Cl3 |
| 9.AD.25 | Holtstamite | Ca3(Al,Mn3+)2(SiO4)2(OH)4 |
| 9.AD.25 | Kerimasite | Ca3Zr2(SiO4)(Fe3+O4)2 |
| 9.AD.25 | Toturite | Ca3Sn2(SiO4)(Fe3+O4)2 |
| 9.AD.25 | Momoiite | (Mn2+,Ca)3V23+(SiO4)3 |
| 9.AD.25 | Eltyubyuite | Ca12Fe103+Si4O32Cl6 |
| 9.AD.25 | Hutcheonite | Ca3Ti2(SiAl2)O12 |
| 9.AD.30 | Coffinite | (U4+,Th)(SiO4)1-x(OH)4x |
| 9.AD.30 | Hafnon | HfSiO4 |
| 9.AD.30 | Thorite | (Th,U)SiO4 |
| 9.AD.30 | Zircon | ZrSiO4 |
| 9.AD.30 | Stetindite | Ce4+SiO4 |
| 9.AD.35 | Huttonite | ThSiO4 |
| 9.AD.35 | Tombarthite-(Y) | Y4(Si,H4)4O12-x(OH)4+2x |
| 9.AD.40 | Eulytine | Bi4(SiO4)3 |
See also
References
- ↑ "Reidite". mindat.org. Hudson Institute of Mineralogy. Retrieved 18 March 2015.
- ↑ "Reidite Mineral Data". Webmineral.com. Retrieved 18 March 2015.
- 1 2 Oskin, Becky. "Rare Mineral Discovered in Ancient Meteorite Impact Crater". Livescience.com. Livescience. Retrieved 24 March 2015.
- ↑ Reddy, S. M., et al. "Precambrian reidite discovered in shocked zircon from the Stac Fada impactite, Scotland." Geology (2015): G37066-1.
External links
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