Argillite (slate). This material, which 
is much diversified in character, was in 
very general use by the tribes n. of 
Mexico for the manufacture of utensils, 
implements, and ornaments, and for 
carvings in general. The typical slates, 
characterized by their decided foliate 
structure, were used to some extent 
for implements; but the more massive 
varieties, such as the greenish striped 
slates of the Eastern states, the argillite 
of New Jersey, Pennsylvania, and the 
states to the s., and the black slate of 
the N. W. coast were usually preferred 
for polished implements and carvings. 
Argillite was much used by the tribes of 
the Delaware and Susquehanna valleys, 
and an ancient quarry of this material, 
situated at Point Pleasant, Pa., has been 
described by Mercer (see Mines and Quar- 
ries). Material from this and other quar- 
ries in the Appalachian region was used 
mainly for flaked implements, including 
leaf-shaped blades, knives, and arrow and 
spear heads, and these are widely dis- 
tributed over the Middle Atlantic states. 
The fine-grained greenish and striped 
slates of the Eastern and Middle states 
and Canada were extensively used in the 
manufacture of several varieties of ob- 
jects of somewhat problematic use, in- 
cluding so-called banner-stones, bird- 
stones, and perforated tablets. It is 
probable that, like the green agates and 
jadeites of Mexico, some varieties of this 
stone had special significance with the 
native tribes. The tribes of the N. W. 
coast employ a fine-grained slate in their 
very artistic carvings, which the Haicla 
obtain chiefly from deposits on Slate 
cr., Queen Charlotte ids. This slate has 
the desirable qualities of being soft and 
easily carved when freshly quarried, and 
of growing harder with time. It is 
black and takes an excellent polish 
(Niblack). See Sculpture and Carving , 
Totem-poles. 
References to the use of argillite and 
slate occur in many works relating to eth- 
nologic and archeologic subjects, but are 
not sufficiently important to be given in 
full. Worthy of special mention are Ab- 
bott, Prim. Industry, 1881; Holmes in 
15th Rep. B. A. E., 1897; Mercer in Pubs. 
Univ. Penn., vi, 1897; Niblack in Rep. 
Nat. Mus. 1888, 1890; Rau in Smithson. 
Rep. 1872, 1873; Squier and Davis in 
Smithson. Cont., i, 1848. (w. h. h. ) 
