Specimens Anhydrite is a relatively common sedimentary mineral that forms massive rock layers. This loss of water produces a reduction in volume of the rock layer and can cause the formation of caverns as the rock shrinks. Good mineral specimens of Anhydrite were extremely rare dispite its common occurrance. However, fine specimens of Anhydrite have been found in Mexico and Peru that show good crystal habit, a nice blue color and even a play of light internally in the crystal.
Color is ordinarily white, gray or colorless but also blue to violet.
Luster is vitreous. Transparency crystals are transparent to translucent. Crystal Habits include the tabular, rectangular box formed by three pinacoids, often elongated in one direction forming a prismatic crystal. Most commonly massive and granular. Cleavage is in three directions forming rectangles, but perfect in one, very good in another and only marginally good in the third direction.