Burgessite Mineral Data

General Burgessite Information
Chemical Formula:	Co2(H2O)4[(AsO3OH)]2•(H2O)
Composition:	Molecular Weight = 487.36 gm
	Calcium 0.16 % Ca 0.23 % CaO
	Cobalt 21.16 % Co 26.91 % CoO
	Nickel 2.77 % Ni 3.52 % NiO
	Arsenic 30.75 % As 47.16 % As₂O₅
	Hydrogen 2.48 % H 22.18 % H₂O
	Oxygen 42.68 % O
	______ ______
	100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:	Co_1.75Ni_0.23Ca_0.02(AsO₃OH)₂•5(H₂O)
Environment:	Purchased as mineral specimen labeled "erythrite" from a mineral dealer; the sample consists of pink rosettes on matrix and was collected in the 1920s. .New structure type.
IMA Status:	Approved IMA 2007 (Dana # Added)
Locality:	Keeley mine, South Lorrain Township, Timiskaming District, Ontario, Canada. Link to MinDat.org Location Data.
Name Origin:	Named for David S. Burgess (born April 18, 1951) of Newington, Connecticut, U.S.A.
Synonym:	IMA2007-055