An interesting, starkly geometrical plate composed of quartz that has completely cast over and replaced fluorite. The quartz varies from 8 mm or so to several cm in thickness. The backside (negative cast) of the specimen is completely covered with sparkling sphalerite in a dense coating of small crystals, while the front has an ENTIRELY different sulfide deposition consisting of isolated galena crystals and isolated sphalerite crystals. Why the front and back should be so different, I hav eno idea. Anyways, though, it is darned neat to look at and is certainly an oldtimer! Ex. Scott Williams dealer stock, too. 14 x 13.1 x 2.5 cm