Search Archived Mineral Specimens
- Availability
- Sold
- Featured
- Featured in Special Editions
- Locality
- Ivigtut Cryolite deposit, Ivigtut, Arsuk Fjord, Sermersooq, Greenland
- Formula
- Na0.5(Al,Mg)2(F,OH)6·H2O
- Size
- SmCabinet 7x5x5cm
- Special Info
- Type Locality
Cryolite matrix with a lot of Siderite hosting many vugs filled with waterclear Thomsenolite and iron-stained, excellent crystals of Ralstonite. On the backside are minute single crystals, hardly noticeable creamy yellow Wulfenite, less than 0.6mm on "hagemannite", a mixture of limonite and thomsenolite. This is a very good combination specimen with good crystals.
- Availability
- Sold
- Locality
- Mohawk mine, Keweenaw Co., Michigan, United States
- Formula
- NiAs2
- Size
- SmCabinet 7x5.5x3cm
- Tagged
- ore mineral , sulfide
Large ore specimen loaded with mostly dull, silvery Rammelsburgite with lessor quantities of brass colored Nickeline with a rosey tinge and tarnished Algodonite. The fact is all three are a little hard to tell apart and this would be a good study specimen with a SEM or a polished section. One side is cut and is likely has been well identified by polished section. Old David Garske label from Rapid City. One side as Annabergite alterations with bead like crystals a clear indication of the nickel content. There are also some bright red alterations (?), which is possibly Pyrargyrite but doesn't seem likely.
- Availability
- Sold
- Locality
- Mohawk mine, Keweenaw Co., Michigan, United States
- Formula
- NiAs2
- Size
- Miniature 5x4x3.5cm
- Tagged
- nickel
Massive silvery or tin white metallic mass of Rammelsbergite nicely represented in this specimen. There are definitely other arsenides in this specimen and also on the side are spherical clusters of a copper or nickel secondary.
- Availability
- Sold
- Featured
- Featured in Special Editions
- Locality
- Langis mine, Cobalt dist., Ontario, Canada
- Formula
- NiAs2
- Size
- Cabinet 11x8x1.5cm
- Tagged
- ore mineral , sulfide , nickel
A large, heavy slab of ore polished on one side. The ores of Cobalt were often slabbed for the geologist to determine the ore characterization such as the texture, how it was mineralized and paragenesis. Rammelsbergite is an ore of nickel and is a nickel arsenide. It is also a member of the Lollingite group. The Rammelsbergite occurs as silvery white anhedral grains to over 1cm. Nickeline, another nickel arsenide, can be seen as brassey or coppery red cores in the Rammelsbergite. Beyond that description, it is impossible to determine visually the phases from one mineral to the other without EDS or microprobe as in the case of the Safflorite, which contains nickel but also cobalt and iron.
