XANTHOCONITE with Proustite on NATIVE Arsenic - image 1

XANTHOCONITE with Proustite on NATIVE Arsenic

Unknown Owner

This is quite a rugged specimen of considerable age, but is significant due to the general rarity of Xanthoconite - a silver arsenic sulphide - and the richness in colour of the vivid blood-red Proustite crystals (another silver arsenic sulphide), particularly from the historically important Jáchymov area in northwest Czechia. Comprising a dense, black, slightly crystallized vuggy Native Arsenic matrix, many of the cavities contain small (sub mm) freestanding terminated crystals of red Proustite as well as darkened purple-red crystals of perhaps Pyrargyrite. The orange Xanthoconite microcrystals are rarer and many are slightly damaged. However, there is considerable potential, given its very large miniature size, for careful splitting to perhaps reveal more cavities within. Additionally, it is accompanied by an albeit a little worn, old Bergdirector Geipel Eisleben label, relating to Max Philipp Geipel (1871-1925) and a more recent Dr Bartnick label.