Bloodstones are a dark green variety of chalcedony which is characterized by the dark red splatters seen throughout it. This gem is a cryptocrystalline quartz and has a hardness of approximately 6.5-7.0 on the Mohs scale of hardness. Inclusions, of amphibole and chlorite contribute to the green part of this gemstone, however, the splashes of red are due to concentrations of iron. Normally, bloodstone have a vitreous to glassy luster.