9.AD.25 (10 ed) |
8/A.08–40 (8 ed)
Hexoctahedral (m3m) |
H-M symbol: (4/m 3 2/m)
|Unit cell||a = 11.819 Å; Z = 8|
|Color||brownish red to brownish yellow|
|Mohs scale hardness||6.5-7.5|
|Diaphaneity||transparent to translucent|
|Refractive index||n = 1.872|
It was named for geologist James Calder who worked on the geology of India. The name was first applied to a rock in manganese deposits in Katkamsandi, Hazaribagh district, Bihar and at Netra, Balaghat district, Madhya Pradesh, India. later transferred to its predominant mineral. In 1909 it was described as a mineral from Otjosondu, Otjozondjupa Region, Namibia.
- James Calder; J. D. Herbert (1981). Geology of the Indian Sub-continent: Observations on Mineralogy, Cypsum, Mines and Mountain Formations (reprint ed.). Cosmo Publications. p. 218.