THE MINING AND QUARRY INDUSTRY I9II 2'J 



the whole they are usually concentrated in certain parts of the 

 deposit so that their presence would not necessarily entail any 

 great waste in the production of pottery material. The existence 

 of trap dikes, of which four were noticed in the quarry face, vary- 

 ing from I inch to 4 feet thick, is of some consequence though 

 probably not a very serious drawback. 



The feldspar includes a pinkish variety which shows the charac- 

 teristic optical properties of microcline and a light-gray oligoclase. 

 They appear to be in about equal amounts. 



In the former operations which were carried on by Mr Roe, the 

 spar was hauled to Crown Point for shipment. The costs of haul- 

 age are reported to have been $1.50 a ton in summer and $1.25 

 in winter. The stretch of road from the quarry to Crown Point 

 Center is over a rough country but chiefly with descending grade. 



Chestertown, Warren county. There are openings in a peg- 

 matite body that is situated on the north side of a high ridge 

 about 3 miles south of Chestertown and 1.5 miles east of the War- 

 rensburg road. They are said to date back about 15 years. The 

 purpose of the operations was to produce mica rather than feld- 

 spar. Two workings may be seen of which the principal one lies 

 to the south and higher up on the ridge. This consists of an open 

 cut about 50 feet long and 15 feet wide on a dike or elongated 

 body of pegmatite that strikes northeast. The limits of the mass 

 are indeterminate except on the east side of the pit where the 

 county rock is exposed a few feet away. The northern pit reveals 

 very little as to the size of the pegmatite mass or the conditions 

 of its occurrence, being a narrow opening which at the time of the 

 writer's visit was filled with water. It may be on a separate body. 



The pegmatite is a coarse intergrowth of white feldspar, quartz 

 and mica. The last named mineral is chiefly biotite with a brownish 

 variety in subordinate amount. The latter may be muscovite but it 

 is not of good quality being in imperfect crystals that show rulings. 

 The largest crystals measure about a foot in diameter. Black tour- 

 malin is quite common in the feldspar and quartz. The feklspar 

 appears in pure masses and also as graphic intergrowths with the 

 quartz. It belongs to the potash variety with the optical properties 

 of microcline. 



Fort Ann, Washington county. An exposure of pegmatite near 

 this place has been worked at different times for feldspar and 

 quartz. It is reported as one of the localities from which quartz 

 was obtained for grinding at the mill that was operated at Fort 



