| Calderite | |
| Category: | Silicate mineral |
| Formula: | (Mn2+Ca)3(Fe3+Al)2(SiO4)3 |
| Imasymbol: | Cdr[1] |
| Strunz: | 9.AD.25 (10 ed) 8/A.08–40 (8 ed) |
| Dana: | 51.4.3a.6 |
| System: | Cubic |
| Class: | Hexoctahedral (mm) H-M symbol: (4/m 2/m) |
| Symmetry: | Iad |
| Unit Cell: | a = 11.819 Å; Z = 8 |
| Color: | brownish red to brownish yellow |
| Cleavage: | None |
| Mohs: | 6.5–7.5 |
| Luster: | Vitreous |
| Streak: | white |
| Diaphaneity: | transparent to translucent |
| Gravity: | 3.756 |
| Opticalprop: | Isotropic |
| Refractive: | n = 1.872 |
| References: | [2] [3] |
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.[3] [4] In 1909 it was described as a mineral from Otjosondu, Otjozondjupa Region, Namibia.[2]