Article · Wikipedia archive · Last revised Jun 4, 2026

Calderite

Calderite is a mineral in the garnet group with the chemical formula (Mn2+, Ca)3(Fe3+, Al)2(SiO4)3.

Last revised
Jun 4, 2026
Read time
≈ 1 min
Length
184 w
Citations
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Source
Calderite
Dark red hexoctahedral crystals on light colored rock
Calderite crystals on matrix from Sunndal Municipality Norway
General
CategorySilicate mineral
Formula(Mn2+Ca)3(Fe3+Al)2(SiO4)3
IMA symbolCdr1
Strunz classification9.AD.25 (10 ed)
8/A.08–40 (8 ed)
Dana classification51.4.3a.6
Crystal systemCubic
Crystal classHexoctahedral (m3m)
H-M symbol: (4/m 3 2/m)
Space groupIa3d
Unit cella = 11.819 Å; Z = 8
Identification
Colorbrownish red to brownish yellow
CleavageNone
Mohs scale hardness6.5–7.5
LusterVitreous
Streakwhite
Diaphaneitytransparent to translucent
Specific gravity3.756
Optical propertiesIsotropic
Refractive indexn = 1.872
References23

Calderite is a mineral in the garnet group with the chemical formula (Mn2+, Ca)3(Fe3+, Al)2(SiO4)3.

It is dark reddish brown to dark yellowish in color and generally granular massive in form.4

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.34 In 1909 it was described as a mineral from Otjosondu, Otjozondjupa Region, Namibia.2

References

References

Further reading

Further reading

  • 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.