Dims: 1.4 x 1.2 x 1.0" (3.6 x 3.1 x 2.5 cm)
Wt: 26.0 g
Brumado Mine, Bahia, Brazil
This small thumbnail specimen consists of a single rhombohedral Magnesite crystal that is mostly covered with a druse of scalenohedral calcites. The Magnesite has dimensions of 1.4 x 0.8 x 0.7" (3.6 x 2.0 x 1.8 cm) and is in good condition, showing only one small spot of human-induced damage besides the cleavage plane on one end. The other exposed faces, however, are natural and though they show some striations, they are clean and smooth, and possess a bright vitreous luster. The Magnesite is generally colorless, though at least one portion of it is visibly rust-stained. It is transparent and moderately clear, containing many cleavage-oriented flaws and internal fractures. The surrounding calcites are also in good condition, though many of them are partly cleaved. The largest of these is much larger than the others, with dimensions of 0.6 x 0.5 x 0.4" (1.5 x 1.3 x 1.0 cm) and an almost tabular form (see the close-up image). Most of the calcites have a pale rust-brown coloration due to included hematite, but all are transparent and quite clear. There is no host rock present.