名詞 orthoclase:

1. a white or colored monoclinic feldspar

or.tho.clase

n.（名詞）
A variety of feldspar, essentially potassium aluminum silicate, KAlSi3O 8, characterized by a monoclinic crystalline structure and found in igneous or granitic rock. Also called potash feldspar
正長(zhǎng)石：一種長(zhǎng)石類，特別是鉀、鋁、硅合物，KAlSi3O 8，其特征為單顆晶體結(jié)構(gòu)，發(fā)現(xiàn)于火山巖或花崗巖中 也作 potash feldspar

來(lái)源：
Greek ortho- [ortho-]
希臘語(yǔ) ortho- [前綴，表.直的，正的.]
Greek klasis [a breaking] from klan [to break]
希臘語(yǔ) klasis [分裂] 源自 klan [打破]