Minerals ~ Anhydrite
Home ~ Menu
Anhydrite Chihuahua, Mexico
Location: The Harvard Museum of Natural History
Photo taken by alcinoe
Anhydrite

Anhydrite is a mineral - anhydrous calcium sulfate, CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium (baryte) and strontium (celestine) sulfates, as might be expected from the chemical formulas. Distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses. The hardness is 3.5 and the specific gravity 2.9. The color is white, sometimes greyish, bluish, or purple. On the best developed of the three cleavages, the lustre is pearly; on other surfaces it is vitreous. When exposed to water, anhydrite readily transforms to the more commonly occurring gypsum, (CaSO42H2O) by the absorption of water. This transformation is reversible, with gypsum or calcium sulfate hemihydrate forming anhydrite by heating to ~200C under normal atmospheric conditions. Anhydrite is commonly associated with calcite, halite, and sulfides such as galena, chalcopyrite, molybdenite, and pyrite in vein deposits. 

SOURCE


Click on Image for Listing
Specimens in Mini Boxes

These specimens are mounted in plastic display boxes that measure 2 1/4" x 1 3/4" x 1" deep. Click on the image to see the full listing of available specimens

Price: Marked under Specimens

Availability:

Each specimen is unique so availability is by image of the piece you select. orders are taken on a first come basis. We have many more in this size range that are not mounted. Those will be in a separate listing





TOP

 

Webpages  2001-2016
Blue Knight Productions