Industrially and commercially they virtually form a part of Troy.
Of these sodium stannate, Na2Sn03, is produced industrially by heating tin with Chile saltpetre and caustic soda, or by fusing very finely powdered tinstone with caustic soda in iron vessels.
Lead chromate, PbCrO 4, is prepared industrially as a yellow pigment, chrome yellow, by precipitating sugar of lead solution with potassium bichromate.
The town is, industrially, remarkable for its paper mills and mines of coal and other minerals.
Minerals are fairly abundant in number, but few are present in sufficient quantity to be industrially important.