A complete floater, crystallized on all sides with slender blade-like crystals of Frankeite radiating in clusters and ball-like aggregates. An incredibly rare mineral, all the best specimens known came from just a few small finds in Bolivia, this is a superb example from what may be the best of those discoveries about 35 years ago. Not long ago Frankeite was often called the rarest Sulfosalt in the world. That may have been true then but today that statement is not true though it is still very super rare. The well-formed balls and clusters are distinctive for this special find at the San Jose Mine. In excellent condition, this displays well from any angle. Ex Dr. Eugene Sensei Collection. As far as we know there have been no more found since about 2005.
Stannite is somewhat rare Sulfide that is not usually attractive unless it has some contrast with its matrix or a very good form. This specimen has a bright sparkling Pyrite matrix with excellent luster that hosts some Stannites in well-formed, complex twinned crystals. The largest Stannite is 1.3 CM across. There is a little Zinkenite in the mix as small but fat needle-like crystals that need a close examination to find. This is from the San Jose Mine which has produced many incredible rare Sulfides and Sulfosalt specimens over the years. This piece is roughly 20 years old from the golden age of this important locale. There is no sign of degradation to the Pyrite and the Stannite is undamaged. A really attractive setting for the dark sulfides nestled in a golden matrix.
Franckeite has always been an incredibly rare mineral and was only known in micro crystals until the major find in 2004 of what was then called Potosiite. This is now known to be a variety of Franckeite with less tin than usual. This was not a large find but the better specimens were quickly gobbled up by collectors and are almost never available now. This piece was one of those major specimens, it is from a collection we are liquidating for the owner and retains the original Kosnar label. In incredible condition for this delicate mineral with individual crystals that reach over 1 CM, in clusters and free standing masses. This piece also has crystals of the original Franckeite that is not the Potosiite variety so this brings two of the world's rarest Sulfosalts on a single matrix. For the species, this is also an esthetic piece, with very three dimensional form and a good metallic luster.
A fine and attractive specimen of this rare Lead, Silver, Antimony "black ugly" mineral. Until the 2004 find, Andorites were one of the rarer Sulfosalts and crystals were always quite tiny. This piece is from that discovery and unusually esthetic, excellent for the size, condition and distinct form of these crystals. The metallic luster and steel to brassy hues are as good as these ever get. Ex Kosnar, there are now very few of this caliber to be found. An outstanding example of this rare Silver specie.
HOLD Franckeite (var. Potosiite)
stock #HOLD 7-R-13-193
San Jose Mine, Oruro
7.5 x 4.6 CM (small cabinet/ large miniature)
Potosiite is the rare Tin poor variety of the rare mineral Franckeite, and was a separate species until it was discredited in 1997. It is still a very rare Sulfide with crystals larger than micros considered huge. From a small find of the worlds largest and best crystals at the San Jose mine, this is a top example with individual crystals to 1.3 cm. For this rare and ugly mineral this is a true killer and even esthetic! This was rated as one of the best 7 pieces found.