Search Archived Mineral Specimens
- Availability
- Sold
- Locality
- West face of Trumbull peak, Mariposa Co., California, United States
- Formula
- Ba6Fe3+3Si8O23(CO3)2Cl3·H2O
- Size
- Thumbnail 2x1x1cm
- Tagged
- carbonate
- Special Info
- Type Locality
Isolated black grains about to 0.5mm with Gillespite in Sanbornite matrix. There are 7-8 grains.
- Availability
- Sold
- Locality
- Trumbull Peak, Mariposa Co., California, United States
- Formula
- Ba6Fe3+3Si8O23(CO3)2Cl3·H2O
- Size
- Thumbnail 1.3x1.2x1cm
- Tagged
- Ba Silicates , barium
- Special Info
- Type Locality
Black grains from about 0.3 to 0.8mm in Sanbornite matrix with red Gillespite. The specimen was identified by the late Gail Dunning, who was one of the authors on the new mineral in 2001 along with Andy Roberts, Grice, and Venance. The paper is located here CLICK.
Fencopperite is probably the rarest of the barium minerals at these deposits. It is a two-locality mineral found only in California.
- Availability
- Sold
- Locality
- Trumbull Peak, Mariposa Co., California, United States
- Formula
- Ba6Fe3+3Si8O23(CO3)2Cl3·H2O
- Size
- Thumbnail 1.3x1x0.7cm
- Special Info
- Type Locality
Fencooperite is a very rare barium silicate carbonate found in two California localities only. The Fencooperite on this specimen consist of 3 or 4 tiny 1mm grains. It really doesn't get much bigger.
- Availability
- Sold
- Locality
- Germania mine, Stevens Co., Washington, United States
- Formula
- Fe2+WO4
- Size
- SmCabinet 7x4x3.5cm
A large chunk of black Ferberite showing some tabular crystals to 1.5cm. I can't say with confidence that is probably a fine specimen for that little known locality, which produced tungsten in the early 1900's.
- Availability
- Sold
- Locality
- Tazna mine, Cerro Tazna, Potosí, Bolivia
- Formula
- Fe2+WO4
- Size
- Thumbnail 3x2.5x3cm
A very nice group of black, shiny Ferberite crystals. All sides of what you see are faces of several crystals. There is one side which shows the detachment point. Tazna has produced many exceptional Ferberite crystals, but they are seldom seen on the market.
- Availability
- Sold
- Locality
- Yaogangxian mine, Chenzhou, Hunan prov., China
- Formula
- Fe2+WO4
- Size
- SmCabinet 8.5x5x4cm
This is really one to be appreciated once in hand though, you will be amazed at the degree of how well crystallized every mineral is. The Fluorite is to about 3mm with purple cores and the Ferberite is large and lustrous to 2.2cm. The brown crystals are actually excellent, thick crystals of Muscovite.
