English word oligoclase comes from English oligo- (Few.), English -clase ((mineralogy) fracture (having a fracture of such a form).)
| Dictionary entry | Language | Definition |
|---|---|---|
| oligo- | English (eng) | Few. |
| -clase | English (eng) | (mineralogy) fracture (having a fracture of such a form). |
| oligoclase | English (eng) | (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. |