This modern knapped  knife was made in volcanic glass Obsidian, and it was hafted on a handle of our local Occoquan River driftwood(species unknown). The full knife measures 7 and 1/2 inches long. Stone knives must be treated differently than steel knives, as obsidian is the most brittle of the stone knives.  They can cut hide and fiber, but are not used aggressively to chop, pry, or carve wood.  The blade was set into the wood with a pine pitch/charcoal mix glue/gap filler mastic, and the exposed Obsidian blade section measures 3 and 3/8th inches long.