I'm a closet knapper. Our region here (SE Oregon) is blessed with tons of obsidian. Chunks turn up in my yard anytime I need to dig a hole or flower bed. Starting with a round cobble, I can knock out smaller points (like 1 to 2 inches) in about 5 or 10 minutes. Larger spear points in the 8 to 10 inch range can take a half hour of so. I'll snap a photo of a few of my samples and put it up this evening. It's been a hobby of mine for years. I frame and sell a few for community fundraisers, but for the most part they simply go into cake tins and are stuffed in corner.
Flint, chert, and more agate like materials are more difficult to knap. That issue can be rectified with some heating of the raw materials to make them a bit more glass like. They are more durable points than our obsidian but not near as sharp.
Huntsman22: The piece in your #4827915 post looks to be some low grade obsidian. I know of a source about 30 miles away. It exhibits some obvious crystalline structure, has some air bubbles, and is a mix of black and red. Some can be quite clear though with light easily passing through a 1 to 2 inch thick sample. It's found about 15 miles east north east of Glass Butte, Oregon. One can find 20 to 30 lb chunks on the surface. Given it's structure, it's not the local material of choice. I've made a few points from that material, and it's a little tougher to work than the more glasslike classic obsidian. There is some similar but even lower grade material near the Geyser Basin area in Yellowstone.
Via chemical finger printing, Oregon obsidian or points thereof, made its way via trading clear across the continent. A very desirable material indeed.
Knapping is the only cheap hobby I've ever undertaken. Materials etc are absolutely free. Now with shooting, photography, and fly fishing, one is looking at serious bucks.
Last edited by 1minute; 03/10/11.
