dì zhì xué jiā / tōng guò / fēn xī / zhèng cháng shí / de / chéng fèn / lái / pàn duàn / yán shí / de / xíng chéng / tiáo jiàn地质学家通过分析正长石的成分来判断岩石的形成条件。Geologists analyze the composition of orthoclase to determine the conditions under which the rock formed.