Roscherite, Mitridatite & Montgomeryite (rare phosphates) Robertson Coll.

Item Description

An exceptional, rich and showy miniature combination of three rare phosphates from the famous Tip Top Mine. Lustrous, black to brown, bladed botryoids of roscherite, a rare Be-phosphate are scattered amongst numerous striking starbursts of lustrous, translucent, creamy montgomeryite lathes. The underlying olive-green crust is mitridaite. The pegmatite was mined for beryllium and is well-known for its rare phosphate species. In fact, the matrix is massive beryl. Ex Kay Robertson Collection # 9910 and acquired from the "South Dakota boys" (Black Hills Institute) at Tucson in 1983. Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record and the 50+ page article in the German Magazine "Mineralien Welt" November-December 2017). An outstanding and rich early combination example rarity from this noted locale. Valued at $700-900 for combination, quality and richness.