Urea, a New Mineral, and Neotype Phosphammite from Western Australia

P. J. Bridge
Government Chemical Laboratories, Perth, Western Australia

Summary: Urea, a new mineral identical with the artificial compound, occurs as crystals associated with phosphammite, ammonian aphthitalite, and weddellite in guano from Toppin Hill, 123° 56′ E., 28° 42′ S., Western Australia. The urea occurs as elongated tetragonal pyramids, space group P4¯21m, a 5·646, c 4·701 Å, X-ray powder data are given. Optical properties: ω 1·484, ε 1·603. Chemical analysis gave urea, CO(NH2)2 96·0, H2O 0·46, Na 0.13, K 0·35, Ca 0·07, Mg 0·03, S 0·11, P 0·24, NH3 < 1·0 %, remainder probably mainly H2O+; urea 96 %, impurities 4 %. Type material is preserved in the collection of the Government Chemical Laboratories, Perth, Western Australia.

Mineralogical Magazine; September 1973 v. 39; no. 303; p. 346-348; DOI: 10.1180/minmag.1973.039.303.11
© 1973, The Mineralogical Society
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