In general this stone is characterized by a medium buff to tan color with light green streaking, although grays and yellowish types are not uncommon.
The pale green banding is, however, distinctive, and it appears this source material was easily obtained along the Ohio River counties and was also workable without heat treating, perhaps accounting for its desirability, despite its overall lack of quality.
Firing also results in an extremely glossy texture, another distinctive characteristic.
Flint Ridge material is of good to excellent workability, once fired.
Its distribution is less widespread, but the quality and workability is good to excellent, and it was also a favorite choice in all early periods.
In addition to dating, these artifacts can often be typed on the basis of where their makers obtained the source material, how far it moved, who else might have used it, and what was needed to produce the artifacts themselves.
This source is almost always a very glossy jet black when fired.
However, it is characterized by distinctive orange flecking, rather than streaking, produced by the oxidizing out of small iron pyrites found in this particular source.
This listing will by no means be a complete one, especially for those sources west of the Rocky Mountains with which the writer has little direct knowledge; but it will be fairly extensive in scope.
In addition to providing the basic source names and locations for many generally known stone quarry and other source materials, I will attempt to also provide a brief description of each stone type which might prove helpful as both an identification tool and as a guide to quality and workmanship potential--both subjects which I feel more than reasonably well-qualified to express.