Black Obsidian (Natural), Gemstone Beads 8mm Round, C Grade, 30 Inches Loose Strung Beads 2 15" strands = 30 inches of beads Approx 90 to 100 beads 8mm round Natural "not dyed" Howlite Mohs hardness 5 to 5-1/2 Natural obsidian is type of volcanic glass