OF JACKSON, NEW HAMrSHIRE. 319 



Since the discovery of the largest tin vein in Jackson, three 

 others of smaller dimensions have been found, which yield a 

 perfectly compact and nearly pure oxide of tin. One of them 

 widens as it descends in the rock. 



Minerals found associated avith the Tin Ore of 

 Jackson, N. H. 



Oxide of tin in crystals and in compact veins of tin-stone, 

 arsenical iron, and arseniate of iron, are abundant. Copper py- 

 rites or bi-sulphuret of copper and iron, in disseminated masses. 

 Native copper," in thin folia, rare ; oxide of iron, not abundant, 

 but mixed with the mica slate of the vein ; iron pyrites, in crys- 

 tals, abundant, disseminated. Wolfram disseminated in the vein- 

 stone not crystallized ; fluor spar, investing the walls of the veins, 

 color light pink, or white and transparent ; mica, brown-colored, 

 in fine scales ; black tourmaline, radiated in small crystals 

 in the granite ; phosphate of lime rare, yellowish-colored crys-. 

 tals ; quartz in crystals and crystalline grains ; it occurs also 

 in thin layers, forming the middle seams in the small veins, 

 serving as a separation of the investing coats of compact tin ore 

 on the sides of the veins, the deposit of tin ore having been made 

 on the walls of the fissure. 



It will be perceived, that the above-mentioned minerals are 

 those which generally occur in the principal tin mines of Corn- 

 wall, Bohemia, and Saxony ; and hence we may infer, that the 

 ch'cumstances under which the ores in these different regions 

 were deposited, were similar, if not identical. It gives us reason 

 to believe, that the New Hampshire tin mines may prove valua- 

 ble. The largest part of the vein was eight inches wide, and it con- 

 tracted to the southward to a vein one inch in width. The small 

 veins run east and west, or across the strata, and they are from 

 one fourth of an inch to one inch wide ; but are much richer than 

 those of larger dimensions. The ore is generally pure compact 

 oxide of tin. It is probable, that, in working the mine, numerous 

 dilatations of the metalliferous lode will occur, forming stock- 

 werkes and pockets of tin-stone. As yet, no excavations have been 



