Exactly what it looks like - a REALLY good specimen of dioptase of the topmost quality, on calcite matrix! Specimens of this quality, are almost unobtainable now and the prices escalate Every year. Since no more has been found from Tsumeb in 30 years, they should only keep going up in value as the stuff is quite simply one of the most beautiful things in the mineral world and nearly all collectors really wants one at some point. This is the best specimen I have had for the 5-10k range in some time.