Dolomite
A common rock-forming rhombohedral mineral from carbonate group, which is used for large objects. It is prized by collectors. Massive variety misnomerly known as dolomite marble. Banded material in red, yellow, green brown, and white from north America is misnomered as wonderstone. Frequently faces of dolomite crystal are curved and some of them so acutely as to form a saddle-shaped crystal.