66 ABORIGINAL MONUMENTS
the more delicate sculptures above referred to, it was adapted for a pipe.
Several other specimens, closely resembling the one last described, have been found at various points upon the surface, but none have been developed from the mounds, Both in material and workmanship they sustain a close relationship to certain “stone idols,” as they have been termed, discovered in Virginia, Tennessee, and elsewhere. One of these, found in the vicinity of Graye Creek, Virginia, and described by Mr. Schooleraft in the first volume of the Society’s Transactions (page 408), is distinguished by a similar “scalp-lock. The orifices communicating with each other, in the back of that figure, would seem to indi- cate that it also was designed for a pipe. The fact that no sculptures of this description have been found in the mounds, and the comparative rudeness which they exhibit, induce the belief that they belong to a different era, and are the work of another and a ruder people.
A large proportion of the mound sculptures are executed ina fine porphyry. It occurs of many shades of color ; some varieties have a greenish brown base, with fine white or black grains; others a light brown base, with white, purple, and violet-tinged specks; but most are red, with white and purplish grounds. In some specimens the base exhibits scarcely any admixture, and strongly resembles the Catlinite, or red pipestone of the Coteau des Prairies, All the examples are of great hardness ; a natural charac- teristic, or measurably the result of the great heat to which they have been subjected. Under heat this porphyry splinters, often in a nearly uniform plane ; and examples have been remarked, partly fused into a porous, dark brown mass. Heat has the effect of rendering the specimens with a red base of a bright black; and some-of the restored sculptures exhibit a striking contrast in the color of their different parts, The primitive locality of this mineral is unknown,
