Kosnarite on Albite

Unknown Owner

With such an unusual chemistry of potassium zirconium phosphate it is no surprise that Kosnarite is so rare - reported from less than ten localities worldwide, four of which are in Brazilian pegmatites. Named in 1993 for Richard Kosnar, an American mineral dealer and specialist in New Jersey and Colorado minerals, it was found at two sites in Maine, USA. The Brazilian finds, of which this specimen is one, were made in about 2014 and provided a colourless variety with exquisite crystal form. This large thumbnail piece displays this perfectly, with sharp, colourless pseudo-octahedral crystals to 3 mm across, richly scattered over larger Albite crystals. It is from the superb systematic collection assembled by brothers Martin and Michael Günther (1951-2007 & 1956-2021).