Show POLISHING PRECIOUS STONES I 1 A balaf description of a very 1 tax tac process the necessary in polish ins a stone Is to slit allt it this is done by means of a thin shee alron disk placed in a horizontal position and made to revolve by very ample machinery a chinery says the philadelphia times diamond dust is applied to botho the edge of the disk and sperm oil to is dropped upon it from a can it if prop ery managed a very small quantity of diamond dust will last all day and not much of it will be lost in order to prevent appreciable loss a table with a raised edge all around it is provided the diamond dust used in polishing stones is made from bort or cheap coarse diamonds after being slit alit the stone is ground on horizontal wheels of lead brass or iron and sometimes 0 of wood these wheels are called laps and the workman who cuts and polishes stones is a lapidary from the latin word lap idarius dadid Lapi lapidaries daries acquire great facility in shaping and polishing stones and from a given pattern are able to produce any object required with great dexterity diamond emery agate or corundum powder is spread op the laps gradually the powder becomes im bedded in the laps and the stone yields to them the stone is held either with the fingers or by wax in the hollow at the end of a stock and is pressed against the revolving laps for the last polish the laps are covered with cloth leather or hard brushes the facets or flat surfaces which give brilliancy to transparent stones are cut by means of a horizontal grinding wheel by the side of which is placed an upright club like piece of wood into this heavy piece of wood in different places a rod is stuck at one end of which the stone is fixed with cement As the wheel revolves the stone is pressed against it and a facet is cut to make a new facet the rod holding the stone is simply stuck in another hole in the club like piece of wood and is thus given a new inclination or angle |