Besides its value as a gem, diamond is employed for various special purposes on account of its great hardness. Bort was first used on the lapidary's wheel by L. von Berquen of Bruges in 1476. It is employed in this manner not only for "cutting" diamonds, but also for faceting other precious stones.
A familiar use of diamond is for cutting glass. For this purpose a diamond must be mounted so that a curved edge between two adjacent facets is employed. This will cut more deeply into the glass than a straight edge, which may be used, however, for writing on glass. Diamonds are also used for drilling glass and porcelain, and for engraving and finishing metal-work, as well as for rock-drilling, which is their most important industrial application. For this purpose carbonado is preferred because it has no tendency to cleavage.
Diamonds are also used for the bearings in watches and electric meters, and, when drilled, for wire-drawing, on account of their great durability. |