quartzite (kwartsit)

[ It is a rock of frequent occurrence, and often forms deposits of great thickne . Quartzite is rarely without a granular structure, either perceptible to the naked eye or visible with the aid of the microscope. Sometimes, however, this structure is with great difficulty perceptible. It is generally held by geologists that quartzite has resulted from the alteration of quartzose sand, pre ure and the presence of siliciferous solutions having thoroughly united the grains of which the rock was originally com posed. The quartzose material of which many veins are made up (material which must have been deposited from a solution) is generally designated quartzite, this sense being reserved for such quartz as is recognized by its stratigraphic position to have been formed from sedimentary material. quartzitic (kwart-sit'ik), a. [ quartz-liquefier (kwârts'lik wē-fi-èr), n. An apparatus in which comminuted auriferous quartz is di olved to liberate the gold. quartz-mill (kwârts'mil), n. 1. A machine for pulverizing quartz, differing in character from the ordinary mill in which the ore is pulverized by stamping, but intended to serve the same purpose. See stamp - mill.-2. An establishment where auriferous quartz is stamped or in some other way reduced to a powder, and the gold separated from it by amalgamation; a stamp-mill. quartzoid (kwârt's oid), a. [ quartzose (kwart'sōs), a. [