flaking

[carpenter374]

hey all. i got some edwards in today. i can take long flakes off a core but they often break. i end up with 2 short flakes instead of one long one. what am i doing wrong? 

[Otoe Bow]

Is the flake breaking, but leaving a long clean scar?  If that's the case, it really doesn't matter, does it?  I don't use a hard hand pad with a groove so almost all my flakes "shatter".  I'm sure some of the other more qualified knappers will jump right in soon. 

Other than that, hows the Edwards? 

Mike

[carpenter374]

the edwards is cake compared to the local stuff i found. ive got a point almost finished from the edwards. still scrachin my head on the local dolomite. its rediculously hard. ive got some good flakes off the stuff but id like to break my tools doin it.

[El Destructo]

You make Points from Dolomite?? The Dolomite here is like a Pinkish White....and seems to be too soft to knapp....but I have never tried it either??

[DanaM]

Dolomite is a type of limestone isn't it, as in unknapable

[Hillbilly]

Depends on the silica content. I believe Alibates flint is actually silicified dolomite if I remember correctly. I've picked up some silicious limestone in TN that knaps halfway decent. Carpenter, are you talking about your spalls that you want to make points from breaking as they come off the core? You may be hitting them too hard or using too hard of a percussor to knock them off with.

[cowboy]

Carpenter - that's a tough one. I've found that if your knocking off really good sized spalls that your grip has a lot to do with it. Set up a good platform and hold the peice on the side - if your hand is at the end of the cobble (where your spall will terminate) that will almost always cause it to break in half. Some of em just break - I certainly can't explain why .

[Otoe Bow]

See, I told you the experts would join in.  I missunderstood your question.  I thought you were talking about pressure flakes, not taking blade flakes off a core. 

Mike

[carpenter374]

alibates is a silicafied dolomite. im gonna make a slightly lighter bopper and see if that helps. the one im usin weighs 10 oz. so i dont want to be touching the side that the blade sized flakes are comin off of? that could be part of the problem i have been layin the core flat on my leg.

[mullet]

  Actually, heavier and slower will help more. Use a good follow through when you strike it and watch your hand support like Paul said.

[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]

Dolomite is a type of limestone isn't it, as in unknapable

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]

el destructo: look up alibates flint with a search engine. read what type of rock it is.

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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