These crystals were a mystery to us when we received them in Madagascar (only 2 pieces). They are columnar crystals, hexagonal in appearance, with a highly lustrous top face (0001). The color is dark brown, the fracture is conchoidal. Only an X-ray (thankfully performed by Mr. Belendorff) yielded the unexpected result that it was a tourmaline. Due to the special training, we are putting this piece online.