Main Discussion Area > Flintknapping
flaking
cowboy:
It's OK to touch the side that the flake is coming off of but you don't want to apply any preassure. The wave traveling through the rock may either turn and go straight out of the rock, or stop where your squeezing it and break the spall in two. I've never had much luck gripping the rock on the end - you wanna grab it by the side. Wish I had a picture :-\.
If your using percussion to thin a spall or bi-face on the other hand, it's better to use the pinch and pull method. Set up your platform - thumb on top, whatever finger you like on bottom, apply preasure and pull away from you with finger, good angle, then bob it - you'll get longer, thinner flakes that way.
El Destructo:
--- Quote from: DanaM on April 15, 2008, 11:26:12 am ---Dolomite is a type of limestone isn't it, as in unknapable ???
--- End quote ---
The stuff We have here called Dolomite....and the whole Caprock around here is Dolomite....is a soft Whitish Pink Limestone that crumbles away when rubbed on ...so I don't see knapping it at all.....
carpenter374:
el destructo: look up alibates flint with a search engine. read what type of rock it is.
El Destructo:
--- Quote from: carpenter374 on April 16, 2008, 02:33:48 am ---el destructo: look up alibates flint with a search engine. read what type of rock it is.
--- End quote ---
I am very aware of what Alibates Flint is....I live 20 miles from The National Monument and Flint Quarries....Alibates Flint is Agatized Dolomite....not just your run of the Mill Dolomite....which is soft and prone to erosion ....and is basically a sedimentary carbonate rock composed of calcium magnesium carbonate...used in Smelting Processes...and Nutritional Supplements.....the Dolomite that the Alibates Flint is under...is a Soft Porous Punky Stone....not good for nothing but Landscaping.....all of the White Rock on the Hillsides here is Dolomite ....it's the Caprock of the Whole Northern Panhandle
Here is what the National Park Service Says about it....
The Alibates flint is more correctly called agatized dolomite, or silicified dolomite. Many archeologists also refer to it as Alibates chert because of it's striking colors. The colors in the flint are caused by trace mineral elements within the silica. The most common colors of red, orange and yellow are caused by iron; blues and deep greens are usually caused by manganese.
There are several theories as to how the flint formed within the dolomite. The most widely accepted theory is that about 670,000 years ago volcanic eruptions occurred in or around what is now called the Yellowstone Country of Wyoming. The resulting silica rich ash drifted upon and above the Permian era dolomite and as slightly acidic rainwater peculated through the ash the silica was able to go into solution. As it soaked into the much older dolomite, the calcium carbonate was washed out leaving the precipitate, silica dioxide (flint or chert), behind.
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El Destructo:
This is what the Dolomite Layer that the Alibates Flint is found under...looks Like....
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