352 NEW YORK STATE MUSEUM 



Argillite. A variety of slate. This term usually refers to 

 Trenton argillite, a compact sl^te that is suitable for making chipped 

 implements. In New York the area in which argilHte implements 

 have been found is limited to the coastal region, the Delaware and 

 Susquehanna valleys and the lower basin of the Hudson. The 

 material wihen found in the form of chipped implements is gener- 

 ally much weathered, having a chalky surface varying from deep red 

 to purple or even a brownish black. On certain sites in the Delaware 

 and Susquehanna valleys in New York and in other localities in New 

 Jersey, chipped argillite implements are found to the exclusion of all 

 other forms. All are old and greatly weathered, which with their 

 exclusiveness gives rise to a theoretical " argillite culture." There is 

 an argillite quarry, showing aboriginal w^orking, at Point Pleasant, 

 Pa. 



Arrowheads, chipped stone. Arrow points of stone were gener- 

 ally small, few except long, slender types, being of a length greater 

 than i^ inches. Heavier forms were used for other purposes than 

 for bow-driven projectile points. The commonest error of the 

 inexperienced collector is to call all chipped flints, regardless of size, 

 arrowheads, but this is simply following erroneous precedents, a 

 course by no means entirely avoided by many who are presumed to 

 be experts. Arrowheads are made of all the varieties of stone that 

 could be used, the material ranging from compact slate to obsidian. 

 In New York the usual materials are hornstone, chert, yellow jasper, 

 quartz, diabase, argillite, chalcedony and slate. To a considerable 

 extent the material used governed the form of the finished imple- 

 ment. The more compact substances, hke the better grades of chert, 

 were the most useful, because of the better chipping qualities of the 

 stone. Quartz, while it w^as a favorite material with the coastal 

 people, was not so good a material as jasper or chert. The quartz 

 point in general is thicker than one of chert. This is due to two 

 reasons, the brittleness of the stone and the more obtuse chip. 

 Some quartz points, however, due to the quality of the stone and the 

 expertness of the workman, are thin and neatly formed. 



While it is true that the material to a limited extent governed the 

 finished forms of arrowheads, to a far greater extent the shape 

 was governed by the desires of the makers of the points. Their 

 first object was to produce a small, narrow point designed for punc- 

 turing and penetrating animal flesh. The point therefore must be 

 sharp and its edges thin. Moreover the size of the point must be 

 such that it would not be so heavv as to take awav from the force of 



