Discrete and isolated cryolite crystals are RARE. This SUPERB specimen is LOADED with crystals to 7 mm on massive cryolite and galena matrix. For the last 200 years, these colorless and lustrous, pseudo cubes, of cryolite, from Greenland, a rare sodium, aluminum, fluoride, have been the standard for the species. The locality is not only now long gone, it's underwater. They mined it below sea level, to get cryolite as an important flux agent for the refining of aluminum. Rust colored siderite is nicely interspersed between the cryolite crystals. This is a very showy, excellent, and good-sized example of this now-vanished species. Ex. Paul Stahl Collection.