oligoclase
/ˈɒlɪgəʊkleɪs/noun
mass noun
- a feldspar mineral common in siliceous igneous rocks, consisting of a sodium-rich plagioclase (with more calcium than albite)奥长石。
词源
mid 19th cent.: from OLIGO- 'relatively little' + Greek klasis 'breaking' (because thought to have a less perfect cleavage than albite).