DESCLOIZITE

ABOUT THE SPECIMEN This is a truly grand statement piece of descloizite from the Berg Aukas Mine, long regarded as the undisputed best for the species! Berg Aukas was mined between 1913 and 1978, so even the most recently discovered pieces are almost half a century old. It's rare that one ever comes across a specimen this large from any locale. Not only does the size make it stand out, the whole face is covered with ‘spearheads’, the most desirable form of the mineral (most large pieces consist of much less attractive habits), and strong amber translucency also stands out in many of the blades. The combination of size, form, color, and visual impact make this one of the best pieces of Berg Aukas descloizite that I've seen anywhere. With the size of this piece, there's naturally some damage present, yet there are just so many quality crystals covering the face of it. This is a truly irreplaceable piece that speaks for itself!   VIDEO   MORE INFO Berg Aukas is a Zn-Pb-V deposit hosted in Precambrian Otavi dolomite - the same carbonate-dominated Otavi Mountainland terrane as Tsumeb - worked from 1920 to 1978 with ore averaging 16.8% Zn, 4% Pb, and 0.93% vanadium pentoxide. Descloizite formed as the dominant supergene vanadate in the oxidized zone surrounding primary sphalerite-willemite orebodies, precipitating in vug and fracture fill within karst breccias as descending meteoric waters mobilized vanadium and deposited it as a lead-zinc vanadate hydroxide. A peer-reviewed Economic Geology study (2007) dated the principal descloizite formation to 24–33 Ma, tying it to post-Gondwanan erosional episodes and Atlantic rifting phases rather than to primary mineralization. Crystals occur as spearpoint-shaped blades in divergent sprays, deep chocolate-brown with a submetallic to resinous luster, occasionally carrying a secondary calcite or dolomite overgrowth on crystal faces that produces a distinctive two-toned appearance. Berg Aukas is the undisputed world standard for the species - no other locality has approached it for crystal size or quality - and with mining permanently ceased in 1978, available material is limited to what was extracted across its six decades of operation.