A HUGE single crystal for the species, showing incredible luster and a deep green saturated color. I have seen many of these over the years, the best purportedly brought out mostly by one mine geologist in the 1960s as I have been told (and see Min Record vol 9 #6, page 341 - 1978), but this thumbnail stands out to me as one of the finest examples I have seen for both the size of the crystal and its sharpness...but most importantly for the luster. With the total "package" of those qualities, most people would guess at this for a primary malachite crystal, I think. But it is a shockingly large, complete, and beautiful libethenite from this, which is considered to have produced the best known crystals of the species. The crystal is a world class thumbnail specimen, complete all around and contacted, not broken, on the bottom From the collection of EJ Immelman.