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Otjosondu, Otjozondjupa Region, Namibia
|System:||Isometric||Colour:||Dark reddish brown to ...|
|Garnet Structural Group|
|Name:||Named in honor of James Calder, an early writer on the geology of India. The name calderite was first applied to a garnet-bearing rock, and later to a poorly defined massive garnet from India (Clark 1993). Dana 6th (1892) page 433 gave an analysis of the Indian mineral but it is not calderite (it only shows trace Mn). Calderite has faded from the literature and was not regarded as a valid species (Fleischer 1971, 1975), until the a manganese-iron garnet reported by Vermass (1952) from Namibia and the calderite reported from Labrador by Klein (1966) was reinvestigated by Dunn (1979). Dunn recommended revalidation of the species citing the data only from the Namibian and Canadian localities. He confirmed the Wabush calderite as being closer to end-member composition (61.5-72.8% calderite, 38.5-27.2% andradite) than those from Namibia (51% calderite, 36% grossular and 13% spessartine).|
This page provides mineralogical data about Calderite.
Classification of Calderite
|IMA status:||Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"|
|Strunz 8th edition ID:||8/A.08-40|
|Nickel-Strunz 10th (pending) edition ID:||9.AD.25|
9 : SILICATES (Germanates)
A : Nesosilicates
D : Nesosilicates without additional anions; cations in  and/or greater coordination
|Dana 8th edition ID:||51.4.3a.6|
51 : NESOSILICATES Insular SiO4 Groups Only
4 : Insular SiO4 Groups Only with cations in  and > coordination
|Hey's CIM Ref.:||14.18.34|
14 : Silicates not Containing Aluminum
18 : Silicates of Mn and Na, K, Mg, Ca or Fe
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Type Occurrence of Calderite
|Co-type Localities:||Wabush iron formation, Labrador, Newfoundland and Labrador, Canada|
Otjosondu, Otjozondjupa Region, Namibia
|Year of Discovery:||1909|
Physical Properties of Calderite
|Colour:||Dark reddish brown to dark yellowish, brown-yellow|
Crystallography of Calderite
|Cell Parameters:||a = 11.81Å|
|Unit Cell Volume:||V 1,647.21 Å³ (Calculated from Unit Cell)|
Optical Data of Calderite
Chemical Properties of Calderite
|Simplified for copy/paste:||(Mn2+,Ca)3(Fe3+,Al)2(SiO4)3|
|Essential elements:||Fe, Mn, O, Si|
|All elements listed in formula:||Al, Ca, Fe, Mn, O, Si|
Relationship of Calderite to other Species
|Member of:||Garnet Structural Group|
|Other Members of Group:|
|Related Minerals - Nickel-Strunz Grouping):|
|Related Minerals - Hey's Index Grouping:|
Other Names for Calderite
|Health Warning:||No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.|
References for Calderite
Dana 6th (1892), 433.
Fermor, L. L. (1926): On the composition of some Indian garnets. Records Geol. Surv. India, 59, Pt. 2, 191-207.
VERMASS, F.H.S. (1952): Manganese-iron garnet from Otjosondu, South-West Africa. Mineralogical Magazine 29, 946-951.
KLEIN, C. (1966): Mineralogy and petrology of the metamorphosed Wabush iron formation, southwest Labrador. Journal of Petrology 7, 246-305.
DUNN, P.J. (1979): On the validity of calderite. Canadian Mineralogist 17, 569-571. American Mineralogist: 66: 1280.
CLARK, A.M. (1993): Hey's Mineral Index (3rd ed.). Chapman and Hall, London, U.K. (107).
Internet Links for Calderite
Localities for Calderite
The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
(TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
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Locality Updated: Telheiro Mine, Santa Luzia, Ourique, Beja District, PortugalFrom Rui Nunes, 21st Dec 2014 23:14:50