Title: Calcium Tungstate(VI)
CAS Registry Number: 7790-75-2
Molecular Formula: CaO4W
Molecular Weight: 287.92
Percent Composition: Ca 13.92%, O 22.23%, W 63.85%
Line Formula: CaWO4
Literature References: Occurs in nature as the mineral scheelite. The article of commerce is usually made by pptn: Boericke, Boericke, US 2390687 (1945); prepn by heating a stoichiometric mixture of CaO or CaCO3 and tungstic acid: Kroger, Nature 159, 674 (1947); prepn of single crystals: Uitert, Soden, J. Appl. Phys. 31, 328 (1960).
Properties: Tetragonal crystals. d 6.06. Practically insol in water. Dec by hot HCl or HNO3.
Density: d 6.06
Use: Very small crystals have been used for injection into malignant tumors, etc., thus affording by transillumination a means of x-ray treatment; for preparing screens for x-ray observations and photographs; in luminous paints; in scintillation counters. |