This blue chalcedony is fine quality material from Malawi, Africa. It may contain some fractures, but all of these pieces will cut fine gems in good sizes. The tan colored rind on some pieces will easily cut away. Chalcedony is the translucent and most desirable form of microcrystalline quartz. It is dense and hard like agate and jasper. Polishes well with diamond or tin oxide, but takes a super glass-like polish with cerium oxide.