Tephrite
A rock classification type
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About Tephrite
Tephritic rocks, with felsics comprising 10-60% foids and alkali feldspar/total feldspar <10%, and <10% olivine.
A group of fine grained, mafic igneous rocks, generally extrusive, of basaltic character, primarily composed of calcic plagioclase, augite, and feldspathoids (typically nepheline), with little or no alkali feldspar or olivine; also, any member of that group; the extrusive equivalent of theralite. With the addition of olivine, the rock would be called a basanite. With decreasing feldspathoids, it grades into alkaline basalt; with increasing feldspathoids, it grades into foidite.
A group of fine grained, mafic igneous rocks, generally extrusive, of basaltic character, primarily composed of calcic plagioclase, augite, and feldspathoids (typically nepheline), with little or no alkali feldspar or olivine; also, any member of that group; the extrusive equivalent of theralite. With the addition of olivine, the rock would be called a basanite. With decreasing feldspathoids, it grades into alkaline basalt; with increasing feldspathoids, it grades into foidite.
Unique Identifiers
Mindat ID:
48563
Long-form identifier:
mindat:1:1:48563:2
Similar Names
| Nephrite | A rock classification type | |
| Nephrite (of Bowen) | A synonym of 'Bowenite' | |
| Tavorite | A valid IMA mineral species - grandfathered | LiFe3+(PO4)(OH) |
| Tephroite | A valid IMA mineral species - grandfathered | Mn22+(SiO4) |
Classification of Tephrite
Tephrite appears in field 14 in the QAPF diagram.^TAS
Sub-divisions of Tephrite
Age distribution
Recorded ages:
Phanerozoic : 71.84 ± 0.51 Ma to 2.30 ± 0.54 Ma - based on 11 recorded ages.
Sample ages:
| Sample ID | Recorded age | Geologic Time | Dating method |
|---|---|---|---|
| 1 | 3.46 ± 1.20 to 2.30 ± 0.54 Ma | Cenozoic | Ar-Ar |
| 2 | 5.4 ± 0.7 Ma | Miocene | K-Ar from a tephrite flow |
| 3 | 7.80 ± 0.20 to 3.10 ± 0.10 Ma | Neogene | K-Ar |
| 4 | 9.97 ± 0.4 to 2.34 ± 0.11 Ma | Cenozoic | |
| 5 | 10.7 ± 0.2 Ma | Miocene | Ar-Ar |
| 6 | 13 Ma | Miocene | Ar-Ar |
| 7 | 14.1 ± 0.6 Ma | Miocene | |
| 8 | 22 ± 12 to 24 ± 12 Ma | Cenozoic | K-Ar fol lava flows from near the bottom of the succession |
| 9 | 30.56 ± 2.59 to 21.05 ± 1.79 Ma | Cenozoic | |
| 10 | 43.78 ± 0.57 Ma | Eocene | Ar-Ar |
| 11 | 71.84 ± 0.51 Ma | Late/Upper Cretaceous | Ar/Ar |
Sample references:
Other Language Names for Tephrite
German:Tephrit
Common Associates
Associations Based on Photo Data:
| 7 photos of Tephrite associated with Haüyne | Na3Ca(Si3Al3)O12(SO4) |
| 1 photo of Tephrite associated with Plagioclase | (Na,Ca)[(Si,Al)AlSi2]O8 |
Internet Links for Tephrite
mindat.org URL:
https://www.mindat.org/min-48563.html
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References for Tephrite
Localities for Tephrite
Showing 217 localities.
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The 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).
All localities listed without proper references should be considered as questionable.
Benešov nad Ploučnicí, Děčín District, Ústí nad Labem Region, Czech Republic