72 



NEW YORK STATE MUSEUM 



Production of feldspar and quartz 



SHORT TONS VALUE YEAR SHORT TONS 



VALUE 



1904 



1905 

 1906 

 1907 

 1908 

 1909 

 I9IO 

 I9II 



9 747 

 19 040 



15 292 

 9 770 



16 413 

 16 III 

 18 012 

 21 802 



$28 463 

 48 500 



44 350 

 36 230 

 68 148 

 52 444 

 64 503 

 75 719 



1912 



1913 

 1914 



1915 

 1916 

 1917 

 1918 



28 584 

 25 680 



23 751 

 22 196 

 20 379 

 14 271 

 12 998 



5115 419 



113 765 

 117 390 



93 152 



115 311 



65 638 



73 230 



PRINCIPAL FELDSPAR OCCURRENCES 



Crown Point. One of the more important pegmatite deposits 

 now quarried is owned by the Crown Point Spar Co. ; it is on Breeds 

 hill south of Crown Point village and a mile or so back from the 

 shore of Lake Champlain and 500 feet above it. The body is a 

 boss rather than a dike, having an oval or rounded outcrop, with 

 a longer diameter that runs northeast-southwest. Its full dimensions 

 have not been revealed but it measures several hundred feet long 

 and at least 300 feet in width. Feldspar occurs in two sorts, a 

 pink potash variety and a greenish soda-bearing feldspar. It occurs 

 in individuals up to 6 or 8 inches in diameter, but is more or less 

 intermixed with quartz which is evenly distributed rather than 

 segregated in large masses. Besides these minerals small amounts 

 of biotite and occasional crystals of titanite, magnetite, zircon, 

 tourmaline, pyrite, chalcopyrite and allanite are present. The 

 pegmatite is now mainly crushed without sorting for use in making 

 artificial stone, prepared roofing, etc.; formerly some pottery spar 

 was sorted and ground separately. A biotite product may also 

 be recovered. The crushed pegmatite is graded in six sizes, ranging 

 from 2^ mesh to very fine sand. The mill is situated at the base of 

 the hill on the Delaware and Hudson railroad, and the rock is con- 

 veyed from the quarry by an overhead tramway. 



Eight miles back of Crown Point on the road to Towner pond 

 and three-fourths of a mile directly south of the latter, at an elevation 

 of HOC feet or more, is the Roe spar-bed actively worked 15 years 

 ago as a source of pottery material. It is notable for the large size 

 of the crystals which attain a cross section of 3 feet or more and 

 are well segregated, so that a product low in quartz can readily be 

 secured. Both potash and soda varieties are present, in about 



