From: Trepca Mine, Kosovo
Size: 12.6 x 8.6 x 9.0cm
No, this is not a ball of steel wool, it is a world-class Boulangerite specimen. This is without a doubt one of the very most delicate mineral specimens in the world, and as such IT IS ONLY AVAILABLE FOR LOCAL PICKUP IN AUSTIN, TEXAS. We cannot ship this specimen for obvious reasons. This is one of the top, if not *the* top Boulangerite specimens in the U.S.A. We acquired this directly from a dealer in Kosovo who hand-carried this in a box in his lap on the airplane from Kosovo to the US, and he is responsible for most of the Trepca specimens that make their way here. According to him there are only 3 Boulangerite specimens this good that he has ever seen: he owns own, a collector in Italy owns another, and then there is this one.
The rarity of these is due to the difficulty in getting them out of the mine in one piece and then transporting them, but this specimen is actually quite durable as long as you don't press hard on it. The Boulangerite doesn't break when you touch it - it just bends. When you walk by the air currents cause the fine hairs to shimmy. Even if you push on it, the hairs are springy and bend. So, it's not really that fragile, just delicate. The hairs are so fine that they have an iridescent sheen to them.
What makes this specimen one of the best in the world is the length of the Boulangerite hairs and the overall size of it. Most Boulangerite specimens have very short hairs - from millimeters ro a few centimeters long. While it's impossible to precisely measure the hair lenghts it appears they are up to 5cm in length which is exceptional! One area has a few small calcite crystals which look like dandruff. This specimen like all Boulangerites has Galena on the bottom. Somehow the Galena associates with minerals in the matrix and surrounding environment to create these incredible mats of fine hairs. The chemical formula is Pb5Sb4S11
If you want something extremely rare and unusual then this is a great specimen to have!