oligoclase
English
Etymology
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d4/Feldspar_-_Oligoclase_Sodium_calcium_aluminum_silicate_near_Crown_Point_Essex_County_New_York_2483.jpg/220px-Feldspar_-_Oligoclase_Sodium_calcium_aluminum_silicate_near_Crown_Point_Essex_County_New_York_2483.jpg)
Noun
oligoclase (usually uncountable, plural oligoclases)
- (mineralogy) A plagioclase feldspar, the second member of the Albite-Anorthite solid solution series. Primarily found as small crystals in impure marble. Oligoclase contains a small amount of calcium substituting for some of the sodium in its formula. Oligoclase with reddish-golden inclusions found in Norway and Canada is called sunstone.
See also
oligoclase on Wikipedia.Wikipedia
- rock
- feldspar
- plagioclase
Further reading
- David Barthelmy (1997–2024) “Oligoclase”, in Webmineral Mineralogy Database.
- “oligoclase”, in Mindat.org[1], Hudson Institute of Mineralogy, 2000–2024.