I found a napped basalt arrow-head with the point broken off, in a fire-pit at a local campsite, near Vanderhoof. The Carrier Indians of the area did not have archery, so it was an arrow point from the Chilko's, who came up to this area on raiding parties. the raiding parties were to capture women for slaves. I've read, they usually just killed all the men.
Basalt also breeaks on a concoidal fracture line, but it is inferior to both obsidian and flint or chert.