Sample formed by several crystals of hercynite, var. picotite, a Mg, Cr rich member of spinel group: (Fe,Mg)(Al,Cr)₂O₄. Collected by Hal Miller in the 1960s, via Dave Shannon. Similar samples discussed in mindat.

Sold

A very good representative of the rare parisite-(Ce) specimens from the Snowbird Mine in Montana. Several crystals of dark golden-brown, pseudohexagonal parisite-(Ce) with a good size are sitting on feldspar matrix. These pieces came out ca. 1955-56, and are very difficult to find on the market, more in matrix! Parisite is a rare, rare-earth carbonate and the Snowbird Mine is a rare earth pegmatite. With a cluster of gersdorffite. From E. Nicolau collection and purchased to Joan Viñals.

Sold

A sculptural and highly unusual, layered nodule of botryoidal, lustrous, rich brown, cassiterite from a very uncommon Montana locality. This variety of cassiterite is called "stream tin", due to the rounded, stream-worn character of the cassiterite. Stream tin was named by Cornish miners from the streams, where the rich deposits were first found in Cornwall. This is excellent, old-time material from the Jaime Bird Collection [Rob Lavinsky sold 2009]. It has two labels attached with the numbers 472 and 4240.
"Wood tin," a cryptocrystalline variety of cassiterite, has bands that resemble the age rings of wood. This variety occurs in locations across the globe, and lapidaries sometimes create ornamental objects and cabochons from it.

An epidote specimen from an unusual North American locality. It occurs as parallel aggregates of very elongated prismatic to acicular crystals, with terminal faces, green in color and transparent.

Laminar rosette-shaped covellite crystals, excellent luster and with an intense violet to purple color, with an aesthetic iridescence. They are disposed on a matrix with pyrite and quartz. The covellite crystal specimens from Butte are highly appreciated by collectors and possibly the best in the world for the species, with only a few exceptions like Sardinia ones, but even those are not as sharp. The quality of this piece is simply excellent. Nowadays, specimens with this fine crystals are rarely seen.