Alstoniteとは 意味・読み方・使い方

Alstonite, also known as bromlite, is a member of the aragonite group of carbonate minerals. It consists of an isomorphous mixture of calcium and barium carbonates in various proportions, BaCa(CO₃)₂, it is triclinic in crystal structure and differs structurally from barytocalcite, which has a monoclinic structure. Simple crystals are not known. The crystals are invariably complex twins, and have the form of doubly terminated pseudo-hexagonal pyramids, like those of witherite but more acute; the faces are horizontally striated and are divided down their center by a twin suture.