- Kara-Oba W Deposit, Karazhal, Karaganda Region, Kazakhstan
- Miniature, 4.0 x 3.5 x 2.2 cm
- Ex. Carnegie Museum
An outstanding fanned spray of creamy colored, bladed, prismatic Bertrandite crystals from the Kara-Oba tungsten deposit in Kazakhstan - a find that many people consider among best of species. This divergent fan radiates from a central point at the bottom and gracefully spreads out laterally. Bertrandite is better known from granite pegmatite occurrences; however, the Kara Oba deposit produced some great Bertrandites over the course of the mine's operational life. Most specimens report crystals of around 2.5 cm as large, but this piece comprises crystals to 4.0 cm in length! Bertrandite is a rare beryllium silicate and this is a great example for the species. Ex. Carnegie Museum collection with label. These came out in the 1980s and 1990s, to market, and then have not been seen since. I have been told the mine is an old military-financed tungsten mine, no longer operating economically. At one time, though, it produced great minerals! This is a competitive, display-quality example of this rare species.