Dacite is an igneous, volcanic rock. It has a grainy texture and is intermediate in composition , consisting mainly of feldspar and quartz. It is often considered a middle ground between obsidian and flint. Dacite usually forms as an intrusive rock, as seen in the dacite domes that formed on top of Mt. Saint Helens. For knapping, it looks more like stone than obsidian and is a bit denser, so it makes great points and blades. Approximately 1 lb.