Blackstone is a trade name for a variety of abundant black stones with a satiny, moderate gloss polish and natural cream-to-brown inclusions.
Beads carved from black stone make stunning, unusual centerpieces for beaded necklaces. Blackstone is made from one of a variety of abundant stones that take a nice polish and can be dyed permanently black. Although they are striking used in southwestern and modern designs, I recently used the carved good fortune symbol bead as a centerpiece with various sized black cinnabar, crystal and black onyx beads and pewter squares as spacers for a beaded necklace that looks both classy and classical. (Now if I just had someplace to wear it.)
The spiritual value of these stones will vary depending on the dyed stones they come from. Some people believe any black stone has a power associated with its blackness that intensifies the spiritual values of the gemstones around them. I love jewelry that includes them because the carvings serve as symbols and reminders of a personal belief, wish or value at the same time they add to the jewelry's beauty.
Because these stones vary, their physical properties vary also. Many are from jasper, a variety of microcrystalline silicon dioxide--a form of chalcedony with a Moh's hardness of 7.