REPORT OF THE DIRECTOR I916 283 



the other hand C. H. Smyth jr.^ who has given most attention to the 

 origin of the ores, shows that the pyrite in large part is undoubtedly 

 of later crystallization than the gangue and that the only difference 

 between the workable deposit and the country rock is the degree to 

 which the metasomatic process has been carried. In evidence of 

 such derivation may be pointed out the abundance of secondary min- 

 erals, chiefly chlorite, developed as an accompaniment of the process. 

 It is noticeable also that graphite is always associated with the ores, 

 in a manner suggestive of precipitating action upon the metallic 

 ingredients. . 



In most examples of the ore the pyrite may be seen to occur in 

 two forms : as finely divided particles more or less evenly distributed 

 through the gangue and as aggregates of coarser grains and crystals 

 in bunches, veinlets and stringers of quite irregular distribution. 

 The relative abundance of the latter type determines to a great 

 extent the relative richness of the ore. Pyrrhotite is not uncommon, 

 but much less abundant than the pyrite. It forms independent 

 bodies and also occurs in a few places in association with the pyrite. 

 Its distribution seems entirely without rule. 



Analyses of representative samples taken from various parts of 

 the district show that the- sulphur content ranges between the 

 approximate limits of 20 and 30 per cent for the most part. The 

 samples on which they were based were taken so as to give, so far 

 as practicable, a fair average of the ore in a working face or 

 exposure. The results are in agreement with mining experience in 

 the district. Ore carrying around 30 per cent has been shipped in 

 some quantity from the Cole property, and the average of that mine 

 is probably over 25 per cent. The Stella and Pyrites deposits are 

 lower grade, with an average of 20 per cent or a little more. 



Experience has shown that the ores will concentrate readily to 

 about 45 per cent sulphur, for which something over 2 tons crude 

 will be required, depending on the individual deposit. 



Of the three properties which have been exploited on a commer- 

 cial scale, the Stella is the single one in present operation. It is 

 worked by the St Lawrence Pyrite Co. and turns out 50,000 tons or 

 more of concentrates a year. The Cole mine, which has been 

 worked intermittently, shipping lump ore, was taken under option 

 by the same company during the past summer and explored. It has 

 an ore richer than the average. The third mine, known as the 

 Pyrites or High Falls, is held on lease by the Oliver Iron Co., of 



' N. Y. State Mus. Bui. 158, 1912. 



