I managed to find a few nice pieces of dioptase on our recent gem show expedition. Quality (and affordable) dioptase is becoming hard to find due to mine closures. For jewelry, the crystals need to be stable and durable enough to hold up to wear and tear--many times dioptase crystals are brittle and loosely rooted within their matrix--the slightest bump knocks them out.
It is amazing how different this gem can be based on where it was mined. Today I finished wrapping pieces from Tsumeb, Namibia & Morenci, Arizona (I have a piece from Kazakhstan also--I'll try to add a picture here when I have a chance to take one).
The Tsumeb variety is what I consider to be classic dioptase... translucent, emerald green, cube shaped crystals ranging from 1-5mm . The crystals are very square and have grown together creating a sheet of crystals, like little green sugar cubes. I've included 2 pictures of the Tsumeb Dioptase set in sterling silver--a full size shot and a rough close-up through my jeweler's loupe to help you see the crystal habit better. This sheet of dioptase crystals is strongly rooted into a white calcite matrix.
Arizona dioptase is an extremely rare find-- particularly in jewelry grade pieces. I have only found 2 pieces in all of my travels! This American variety of dioptase has very tiny needle-like emerald green crystals tightly packed together, like a blanket of microscopic emerald green grass, rooted into a stone matrix of cuprite and chrysacola. The crystals range in size from fractions of a mm up to 1x2mm. Tiny-but don't be fooled, they glimmer with subtle sparkle in the light and are quite durable--I cleaned this piece with a toothbrush and dish detergent.
To visit my previous entry on this gem click here; this article has pictures of Russian dioptase that will make you drool! :)