By Gerd Dreher, Idar-Oberstein, Germany Virtually optically clear - with only minor inclusions ? this large boulder of rock crystal quartz from Brazil has been carved in a technique called ?reverse intaglio? carving depicting a very large branching coral. The base is also reversed intaglio carved, with a stippled effect from the bottom to resemble the ocean floor with carved designs of starfish and scallop shell. Monogram signature GD. Measuring 9 ? x 8 x 2 ? in