Stibiotantalite (fine thumbnail)

Item Description

Stibiotantalite is a rare antimony tantalum niobium oxide species, most famously found at the Himalaya Mine in California. Specimens from Brazil are exceedingly rare, and this particular piece is one of only a few I've seen from the entire country. I honestly can't remember seeing a better thumbnail from Brazil. This piece is a fine, sharp, very well-formed, somewhat thick, orthorhombic crystal with lustrous, smooth faces, especially on the termination. The piece is essentially black and opaque, as I could not get any light to come through even with strong backlighting, but there is a slight dark yellowish hue on the underside, which is indicative of Stibiotantalite, which often has some kind of yellow hue. I looked at the piece with a loupe, and I can't find any damage on the termination, though the crystal is contacted on the underside. It's a truly impressive and worthwhile example of a mineral that is seldom seen from Brazil, and would make a great addition to any thumbnail or rare mineral collection. This piece was mined in the late 1990s and comes from the collection of Brian Kosnar. It's hard to put a fair market value on a piece like this, but I hold it in high regard for its quality and rare locality.