Bipyramidal crystals of Quartz after Beta-Quartz. Beta Quartz is a high temperature polymorph of Silica - similar to Quartz, but with higher symmetry. I suggest reading the Mindat page on it - they do a far better job of explaining than I ever would.
These specimens are bi-pyramidal, with horizontal symmetry. These are extremely rare crystals and we may not be able to find any more stock!
These all come from the Sukabumi Regency, West Java, Indonesia.
I have graded them into three quality grades; A being pieces with good intact edges and good crystal form, B being pieces with some edge damage but generally good crystal form, C being pieces with more than 25% missing, or that have been weathered/eroded.