Dolomite. CaMg(CO3)2 is an anhydrous carbonate mineral, sometimes referred to as dolostone. It has several industrial uses including the production of float glass, and as an additive to soil and potting mixtures as a pH buffer. This specimen is a tangled collection of tabular crystals with curved faces, which is the normal habit for dolomite . The source of this specimen is from one of the limestone/dolomite quarries in Sligo, Ireland.