Prosopite (Pseudo. After Topaz?)
Santa Rosa Mine, Mazapil, Zecatecas, Mexico
Small Cabinet, 7.1 x 4.7 x 3.4 cm
Ex. Evan Jones
I admit to having had no idea what this was until I looked it up. I got it from Evan Jones who had the same problem, getting it for his Mexican collection only because he'd a) never heard of it either and b) it was pretty. Prosopite can form as an alteration product of Topaz in Topaz-rich greissens, according to Mindat ( One imagines this is what happenned here.