A gorgeous gem crystal of a very common species that is very rarely seen in gem quality crystals: Sanidine is a Potassium Feldspar that is found in various localities around the world, but GEM quality material is scarce, especially in larger pieces. Recent analysis has shown that many of the famous yellow "Orthoclase" stones from the classic locality of Itrongay in Madagascar are actually some of the finest gem SANIDINES extant (I did not realize this until recently, myself). The best of these crystals are good sized for the species (especially in gem material), but to find gem quality Feldspar with any color whatsoever is notable. This one has GREAT color saturation and uniformity of color. It is almost complete all around, with just a few contacts around the periphery - in way better condition than most crystals of this size after surviving collecting in remote Itrongay and then the gemstone market. As well, most of the good ones, as with this, are decades out of the ground. This amazingly large stone is certainly noteworthy. We also have a few cut gems of comparable quality, for a cut and rough set if one wishes to assemble it. From the Marty Zinn collection (sold off in 2003). Joe Budd photos.