Heritage Auctions Presents: Diorite
A rock classification type
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About Diorite
Name:
Etymol: Greek diorizein, to distinguish, in reference to the fact that the characteristic mineral, hornblende, is usually identifiable megascopically.
A dioritic rock with dominant plagioclase, significant mafic minerals, <5% quartz and <10% alkali feldspar/ total feldspar on the QAPF diagram.
Plutonic, coarse grained igneous rocks intermediate in composition between acidic and basic, characteristically more mafic than most granitic and syenitic rocks. It is typically composed mostly of intermediate to sodic plagioclase (oligoclase - andesine), dark-colored amphibole (esp. hornblende), calcic clinopyroxene, and sometimes a small amount of quartz; also, any rock in that group; the approximate intrusive equivalent of andesite. Diorite grades into monzonite with an increase in the alkali feldspar content, and gabbro with an increase in calcic plagioclase.
See also: diabase, dolerite
Compare with: dolerite, gabbro
Plutonic, coarse grained igneous rocks intermediate in composition between acidic and basic, characteristically more mafic than most granitic and syenitic rocks. It is typically composed mostly of intermediate to sodic plagioclase (oligoclase - andesine), dark-colored amphibole (esp. hornblende), calcic clinopyroxene, and sometimes a small amount of quartz; also, any rock in that group; the approximate intrusive equivalent of andesite. Diorite grades into monzonite with an increase in the alkali feldspar content, and gabbro with an increase in calcic plagioclase.
See also: diabase, dolerite
Compare with: dolerite, gabbro
Unique Identifiers
Mindat ID:
48226
Long-form identifier:
mindat:1:1:48226:4
Classification of Diorite
Diorite is in section 10 of the QAPF diagram.
Sub-divisions of Diorite
Mineralogy of Diorite
Essential minerals - these are minerals that are required within the classification of this rock:
| Feldspar > Plagioclase | (Na,Ca)[(Si,Al)AlSi2]O8 |
Non-essential minerals - these minerals are common, sometimes major components, but are not always present:
Other Language Names for Diorite
Irish Gaelic:Dióirít
Varieties of Diorite
| Dioritite | An obsolete name for a diorite or diorite-aplite occurring as dykes. |
| Orbicular diorite | A diorite showing orbicular features. |
| Spiemontite | An obsolete term for a variety of fine-grained diorite. |
Common Associates
Associated Minerals Based on Photo Data:
| 3 photos of Diorite associated with Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| 3 photos of Diorite associated with Feldspar Group | |
| 3 photos of Diorite associated with Eudialyte | Na15Ca6Fe3Zr3Si(Si25O73)(O,OH,H2O)3(Cl,OH)2 |
| 3 photos of Diorite associated with Khibinite | |
| 2 photos of Diorite associated with Hibonite | CaAl12O19 |
| 1 photo of Diorite associated with Pigeonite | (CaxMgyFez)(Mgy1Fez1)Si2O6 |
| 1 photo of Diorite associated with Amphibole Supergroup | AB2C5((Si,Al,Ti)8O22)(OH,F,Cl,O)2 |
| 1 photo of Diorite associated with Granite |
Internet Links for Diorite
mindat.org URL:
https://www.mindat.org/min-48226.html
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References for Diorite
Reference List:
Teletín quarry, Krňany, Benešov District, Central Bohemian Region, Czech Republic