Purchased directly from the famous Tsumeb specialist dealers Miriam and Julius Zweibel, this is an important example of one of the most desired styles of Tsumeb dioptase in combination with the best-quality stark white contrasting calcite, from the early modern mining heyday here. It is dated to 1978 when he purchased the piece, which places it before the "motherlode" of tables of beautiful dioptase came out (though mostly not associated with calcite like this), and that explains why we see so few of this particular style on the market (I was never quite sure of the date on these, and thought it early 1980s, but apparently it was some time back, just as the Zweibels were really becoming the dominant player in Tsumeb minerals). The piece is as close to pristine as you can wish, with just a few very tiny and trivial dings, and one broken crystal area on the bottom as I would display the piece on a base anyways (first photo). It is exceptionally 3-dimensional, and exceptionally sparkling. The calcite is stark, snow white. The contrast is of green on white, I think most people will agree, the best and most desired display style for a Dioptase. Because this is mounded up, and presents with depth as well as contrast, I regard it as an exceptional example of the style, not surpassed after over 40 years.