Tiger Chert - artififacts and rough, newbie

[Daviddscbs]

I have a very newbie question. I apologize in advance for my lack of knowledge, I am basically a lapidary and mineral guy. I went to an estate sale recently and saw dozens of tiger chert artifacts (mainly scrappers and other tools, not arrowheads) and wyoming tiger chert rough that knappers could use. I made of note to research the material but did not get any. The material had very distinct bands of black and brown. So far what I have found is that Wyoming tiger chert is fairly uncommon and that these artifacts are fairly popular. Is my understanding about the rarity of tiger chert correct? Would knappers be interested in this material? I saw 50+ pounds of rough if not more. Given the other items offered at the estate sale I imagine the artifacts where collected in far north-east CO or in fart SW Wyoming.
Thanks.
David

[sneakygroundbuzzard]

ive never knapped tiger chert
but as a knapper i can tell you this
all lithic material has high grades and low grades and everything in between
the higher the grade the better it knapps
i would have to see pics of it before i would say whether or not i would any to knapp
dont know if its rare or not

[Daviddscbs]

Can you tell me what to look for to distinguish between high grade and low grade knapping material?.  I am familiar with judging mineral specimens and some lapidary material but knapping is new to me.  Sorry I don't have any photos.   I may have a chance to buy some of the material latter in the month.  Considering I grew up in the Flint Hills region of Kansas my lack of knowledge on this topic is kind of funny.
Thanks for your help.

[chase]

Here is a little information on Tiger Chert, from our Information center.
Oh and welcome to AH.com :welcome:

http://www.arrowheads.com/index.php/forum/lithic-material-types-a-sourcing/79812-tiger-chert-nw-colorado-sw-wyoming

[sneakygroundbuzzard]

well in general a piece of chert or flint will produce a very nice and clean concoidial fracture when struck properly
it will also be very slick and smooth and glassy looking on the surface that was fractured and a flake has been removed from
also it wont need heat treating to knapp well
  a concodial fracture,hmmmm let me think of how to describe it best
  when a rock or bb hits the windshield of you car or a glass window on your house
it leaves a very clean cone shaped fracture
in flint knapping thats what we try to produce when we take a flake from the mother rock
except we only want to remove a half cone
hope that helps
if you decide to buy some,post some pics
if its good looking material and your willing to sell some
if the price is right i may be interested in buying some

[sneakygroundbuzzard]

chase, i looked at the pics in the link you posted
the last pic almost looks like Polish flint,very closely resembles it

[Daviddscbs]

Thanks for the tips on grading the material.  Hopefully I will be able to pick some up later in October.