Oneillite Mineral Data

General Oneillite Information
Chemical Formula:	Na15Ca3Mn3Fe++3Zr3Nb(Si25O73)(O,OH,H2O)3(OH,Cl)2
Composition:	Molecular Weight = 3,128.56 gm
	Sodium 11.02 % Na 14.86 % Na₂O
	Calcium 3.84 % Ca 5.38 % CaO
	Zirconium 8.75 % Zr 11.82 % ZrO₂
	Manganese 5.27 % Mn 6.80 % MnO
	Niobium 2.97 % Nb 4.25 % Nb₂O₅
	Iron 5.36 % Fe 6.89 % FeO
	Silicon 22.44 % Si 48.01 % SiO₂
	Hydrogen 0.10 % H 0.89 % H₂O
	Chlorine 0.57 % Cl 0.57 % Cl
	- % Cl -0.13 % -O=Cl₂
	Oxygen 39.68 % O
	______ ______
	100.00 % 99.34 % = TOTAL OXIDE
Empirical Formula:	Na₁₅Ca₃Mn²⁺₃Fe²⁺₃Zr₃NbSi₂₅O_74.8(OH)_2.5(H₂O)_0.3Cl_0.5
Environment:	Found in nepheline syenite at the contact between a vein of fine-grained albite and the host rock. A member of the Eudialyte group.
IMA Status:	Approved IMA 1998 (Dana # Added)
Locality:	Poudrette quarry, Mont Saint-Hilaire, Rouville County, Quebec, Canada. Link to MinDat.org Location Data.
Name Origin:	Named after John Johnston O�Neill (1886-1966), geologist with the Geological Survey of Canada, Ottawa, and later, Professor of geology, Dean of Science and Dean of Engineering at Mc Gill University, Montreal, Canada.
Synonym:	IMA1998-064