Dacite Spalled In Half

When we met I handed him the rock and after a brief examination he said “I’m not sure this is obsidian, but let’s open it up and see what we’ve got here”. He selected a baseball sized hammerstone and placed a leather apron over his thigh, then layed the rock on the side of his thigh and with an arched swing, struck the rock’s edge with a downward blow. After a few strikes, the stone split open the full length of the rock. He said “oh… this is dacite… similar to obsidian but different. Dacite is a volcanic rock that has cooled under salt water and it works differently than obsidian”.

Not too surprising, different materials require different tools to achieve the best results. A gritty-surfaced hammerstone worked best in this case but a hardened dogwood billet works best for harder stones like quartz and rhyolite. The effectiveness of the tool has to do with it’s surface contact time during the strike.

Dacite Flake

After having observed the reduction of the first half of the rock I now have the remaining half of the rock to work with to apply what I have learned from his demonstration. I expect that exciting times as well as frustrating times lie ahead but I’m sure that they will be rewarding in my quest to master flintknapping skills.

Obsidian, a glassy rock, is a favored material but only found on the West Coast. A number of other states have flint. Here, in North Carolina, there is no flint. The local material in this region is quartz that is tough to knap and can be found in various shades of white. However a similar material to flint is found on the Southern boarder of the state that is called rhyolite and is usually greenish-gray in color. When this material is found locally you know that it was “imported” and is referred to as “trade stone” because Indians would trade goods to obtain this nicer material to fashion into arrowheads.

Local arrowhead hunters recommend that one of the best places to look for arrowheads is in a freshly plowed field after a heavy rain. The artifacts in the photo were not found in a field but rather in the mulch beds around an apartment complex that I tend. Fortunately for me the general public does not recognize these as artifacts and have been left as “rocks”. Having done some flint knapping I can recognize the signs of man-made shapes created by hammer stones, billets, and pressure flaking.

The two quartz pieces are rough compared to the finished points using trade-stone. Arrowheads can have different shapes based on tribes and differing eras. Some artifacts that are roughly shaped mid process are known as pre-faces. The rhyolite shown here is a piece off of a stone as it was reduced to the final shape. This is known as a spall from the spalling process. It’s not an arrowhead but a byproduct of the process to make one.

My guess is that the grounds where the mulch was processed happened to be located over old Indian campgrounds and were picked up when they loaded their trucks for delivery. It’s a delight to discover these bits of history in the course of tending the landscaped grounds. What can you find in your gardens?