Chaoite
A valid IMA mineral species
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About Chaoite
Formula:
C
Colour:
Black
Hardness:
1 - 2
Specific Gravity:
3.43 (Calculated)
Crystal System:
Hexagonal
Name:
Named by A. El Goresy in 1969 (described a year earlier) in honor of Edward Ching-Te Chao (30 November 1919, Suzhou, China - 3 February 2008, Fairfax, Virginia, USA), geologist and petrologist with the United States Geological Survey, for his pioneering work on impact metamorphism. Chaoite is formed during meteorite impacts, as are two silica minerals that Dr. Chao famously discovered: coesite and stishovite.
Type Locality:
Polymorph of:
This page provides mineralogical data about Chaoite.
Unique Identifiers
Mindat ID:
1207
Long-form identifier:
mindat:1:1:1207:8
GUID
(UUID V4):
(UUID V4):
2b43a58b-d98d-48f6-a150-964b25481c84
IMA Classification of Chaoite
Approved
Approval year:
1968
First published:
1968
Classification of Chaoite
1.CB.05b
1 : ELEMENTS (Metals and intermetallic alloys; metalloids and nonmetals; carbides, silicides, nitrides, phosphides)
C : Metalloids and Nonmetals
B : Carbon-silicon family
1 : ELEMENTS (Metals and intermetallic alloys; metalloids and nonmetals; carbides, silicides, nitrides, phosphides)
C : Metalloids and Nonmetals
B : Carbon-silicon family
Dana 7th ed.:
1.3.5.4
1.3.6.4
1 : NATIVE ELEMENTS AND ALLOYS
3 : Semi-metals and non-metals
1 : NATIVE ELEMENTS AND ALLOYS
3 : Semi-metals and non-metals
1.26
1 : Elements and Alloys (including the arsenides, antimonides and bismuthides of Cu, Ag and Au)
1 : Elements and Alloys (including the arsenides, antimonides and bismuthides of Cu, Ag and Au)
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Symbol | Source | Reference |
---|---|---|
Ch | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Chaoite
Chemistry of Chaoite
Mindat Formula:
C
Elements listed:
Common Impurities:
Si,Cl
Crystallography of Chaoite
Crystal System:
Hexagonal
Class (H-M):
6/mmm (6/m 2/m 2/m) - Dihexagonal Dipyramidal
Space Group:
P6/mmm
Setting:
P6/mmm
Cell Parameters:
a = 8.948 Å, c = 14.078 Å
Ratio:
a:c = 1 : 1.573
Unit Cell V:
976.17 ų (Calculated from Unit Cell)
Z:
168
Morphology:
Thin lamellae alternating with graphite.
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
4.47 Å | (100) |
4.26 Å | (100) |
4.12 Å | (80) |
3.71 Å | (40) |
3.03 Å | (60) |
2.55 Å | (60) |
2.28 Å | (60) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 2: Planetesimal differentiation and alteration | 4.566-4.550 |
6 : Secondary asteroid phases | 4.566-4.560 |
Near-surface Processes | |
30 : Terrestrial impact minerals |
Geological Setting:
Meteorites
Type Occurrence of Chaoite
General Appearance of Type Material:
Thin lamellae to 15 µm alternating with graphite.
Place of Conservation of Type Material:
Unknown
Geological Setting of Type Material:
Shock metamorphosed graphite bearing gneiss.
Reference:
El Goresy, A., Donnay, G. (1968) A new allotropic form of carbon from the Ries crater. Science: 161: 363-364.
Synonyms of Chaoite
Other Language Names for Chaoite
Common Associates
Related Minerals - Strunz-mindat Grouping
1.CB. | Tartarosite | C |
1.CB.05a | Graphite | C |
1.CB.05c | Fullerite | C60 |
1.CB.10a | Diamond | C |
1.CB.10b | Lonsdaleite | C |
1.CB.15 | Silicon | Si |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Chaoite
mindat.org URL:
https://www.mindat.org/min-1207.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Chaoite
Localities for Chaoite
Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Finland | |
| Vdovykin (4) |
Germany (TL) | |
| Amer. Mineral. +1 other reference |
India | |
| Mineralogical Society of America - ... |
| Mineralogical Society of America - ... |
Russia | |
| Pavel.M. Kartashov (n.d.) |
Quick NavTopAbout ChaoiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Möttingen, Donau-Ries District, Swabia, Bavaria, Germany