Stillwellite is a rare REE borosilicate and some of the best crystals of the species originate from the rugged mountains of Tajikistan. This is one of the better crystals collected from a remarkable pocket in September of 2004. It features a huge 2cm, translucent medium brown-yellow (normal indoor lighting) crystal on alkaline pegmatite matrix. Interestingly, they COLOR CHANGE from red in halogen or sunlight to YELLOW in fluorescent light. This is a superb, nearly complete crystal for the species, as well as being unusually attractive for the mineral. An old The Arkenstone label accompanies the piece from Rob's days in California while going to grad school. He bought this from the Fersman Museum in the mid 1990s; the museum label is still included with the piece. It is exceptional for the species. From an old find not repeated since.