Here's some notes on what I've found so far. All of these were flaked on 3-7, 3-10, and 3-21.
There were two main grades of stone in the group Turbo left. The green Rhyolite is very high grade stuff, almost on par with high-end heat treated Novaculite. It is smooth, flakes easily, and takes pressure flaking rather well. The gray Rhyolite is grainier, and a lot tougher. This stuff takes a lot of force to flake, and a lot of platform prep to flake well. That being said, with proper set-up and force, the flakes come off rather well and predictably.
Four preforms... 2 gray, 2 green. The two green are retouched from the ones above.
Thickness of one of the gray pre-forms:
The finished green point:
Thickness of the green point:
I will post more detailed pics of the gray Rhyolite along with platform preparation and flakes taken with the scars. This stuff, including the gray, is very fine stone and really a joy to work. I have a habit of striking obsidian too hard and shattering it. This Rhyolite stands up much better to high force levels, especially the gray species.