Sanidine gem crystal ex Jack Halpern

Item Description

A stunning GEM crystal of this rare feldspar species makes for an imposing miniature! This material is some of the best feldspar in the world, and yet all too often it is cut for the gem rough, and making beautiful cut gems. Few enough crystals of this quality were preserved, and the glory days for the finds were in the late 1990s and early 2000s. At one time these were all labeld as Orthoclase, but they are actually Sanidine, another valid feldspar species but fully disordered in its Al & Si distribution in its chemical composition.   This miniature is VERY RARE AND LARGE for the fine condition it is in, only being cleaved at the bottom where contacted. The crystal is 100% gem, golden, totally transparent, with many of the crystal faces present. It is particularly equant and crystallized sharply, wehreas many of them are more rounded and lumpy, so we find this a particularly good specimen for the mineral collector compared to most in the size range. The faces are glassy and textured with small, curvy trenches that look like subparallel and tiny worm tracks - mesmerizing up close! Bonus - notice the reflective rainbow pattern inside - not sure what causes that! Valued $2500-3500. 65 grams of mostly clean, cuttable facet grade gem feldspar!