Cumengite Mineral Data

General Cumengite Information
Chemical Formula:	Cu20Pb21Cl42(OH)40•6H2O
Composition:	Molecular Weight = 7,899.52 gm
	Copper 16.09 % Cu 20.14 % CuO
	Hydrogen 0.66 % H 5.93 % H₂O
	Lead 55.08 % Pb 59.34 % PbO
	Chlorine 18.85 % Cl 18.85 % Cl
	- % Cl -4.25 % -O=Cl₂
	Oxygen 9.32 % O
	______ ______
	100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:	Cu₂₀Pb₂₁Cl₄₂(OH)₄₀•6(H₂O)
Environment:	Oxidized zone of sedimentary copper ores associated with boleite.
IMA Status:	Valid Species (Pre-IMA) 1893
Locality:	Boleo, near Santa Rosalia, Baja California Sur. Link to MinDat.org Location Data.
Name Origin:	Named for Edouard Cumenge (1828-1902), French mining engineer for the Boleo mines.
Synonym:	Cumengeite