Mineralpedia Details for Roscherite
Named after German mineral collector Walter Roscher. Roscherite can be found in granite and pegmatite cavities in localities including Germany, England, Brazil, and the USA including at the Tip Top mine here in Black Hills of South Dakota.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/roscherite.pdf
Roscherite from Tip Top mine, Custer Co., South Dakota, United States
Red rosettes of Roscherite with acicular white Tiptopite and white balls of Englishite less than 1mm.
Dark, olive green crystal, 1mm. Unusually rare and large crystal for Roscherite (XRD).
The last two photos are lilac Ruscherite with pink Montgomeryite. A
The Roscherites at Tip Top are crystallized in a range of colors and the lilac colored crystals may be Zanazziite, the Mg member. The pink rosettes are Montgomeryite clusters to 1.5mm. These clusters, when viewed under the scope are very lustrous and distinct.
This is the most desirable color for Roscherite. I have never seen better Roscherite than the Tip Top mine. The Roscherite group is growing, but as of yet, all Roscherites from the Tip Top mine remain plain Roscherite. It is difficult to discern the different Roscherites based on color alone, and there are several colors at the Tip Top mine (purple, orange, black). I have had three of the foremost mineralogist in the world check them out and each gave inconclusive results based on zonations and impurities. Anyhow, this is a fine and very good specimen of Roscherite with superb single crystals and clusters with red Montgomerite and scattered spheroids of Hurlbutite. Beryl matrix.