This is a very rare drill core section, complete all around and showing clearly its origins, that cut into a natural pocket of sulfur from deep in the ground! It has rich, yellow, gemmy crystals of sulfur to over 1 cm, perched on contrasting spiky white calcite crystals. It is beautiful! Geologists during the 1970s and 1980s used to keep these rare core pockets of sulfur whenfound, and give them as gifts around the area here in Texas. In practice, they are almost impossible to find on the market for this reason. After all, nobody really could have afforded to collect them as specimens per se, not when spending tens of thousands of dollars per drill, if not more! And then, many didn't go to collectors, but to mining companies for unique office decor. In a way, that makes these the world's most expensively mined mineral specimens, I suppose. I have seen only half a dozen over the years since moved to Texas the first time, in 1991. These two ar ethe best I have actually seen up for sale. 12.8 x 12.6 x 9.8 cm