Question on mookite, agate, and jasper preforms

[gutpile]

question..just ordered some from craig 3 to 4 inches preforms of above..(Haven't work this stuff before)..do you guys pressure flake the first pass or percussion and if so which type of tool..copper or bone..just worked some agate I had that responded better to light taps with small copper than bone...I had tried to pressure flake the skin off and it got to stepping on me...so I came back on the other side with copper to clean it up..also which method do you guys use to establish your edge with as little as possible of size reduction...?.....gut

[mullet]

I pressure flake with copper a short pass all the way around it. Then grind it good to make it ovate and then come back and try to run the last set of flakes to the center. Is that agate heat treated? If not it will be a booger to flake and the colors won't be near as brite.

[gutpile]

yes it is heat treated..think this last batch wasn't maybe that is why it was so tough to pressure flake...