A highly unusual Tsumeb oddity, and the only large example I have seen in good quality of this style, this piece features sharp classic Tsumeb calcite rhombohedra with a bit of a surprise inside. Rhombs of lustrous and translucent, colorless calcite, to 3 cm on an edge, are invested with needle-like inclusions of manganese arranged as elongated dendrites growing through the calcites. Why? How? We do not know. I can only say I have seen a few of these with manganese or duftite inclusions of similar style, and always wondered myself how they form. This occurrence appears to be very rare. 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.