Tsumeb produced a fabulous range of style sand colors of calcite, but I have only ever seen two other specimens from this highly unique pocket (and this was the best of them, that I saw). Highly lustrous and partially transparent, this rich golden-amber calcite specimen is dominated by the largest crystal, measuring 3.2 cm in length. The large crystal is beautifully framed at the base by smaller, yet colorful calcite crystals. Small spots of red-brown apparently are the result of oxidation of another species that was associated with it and are ingrown into the crystal (as the color does not wash off when you clean it!). We always believed the red color is due to iron, unusual for Tsumeb, but it could be manganese, perhaps. Ex. Marshall Sussman Tsumeb collection, from his fabulous and most important first collection built in Chicago and sold to me in 2004, as I was a calcite collector at the time (since the age of 12 when I started!) I kept this for myself in the deal and have owned it since then until now.