Page:A treatise on diamonds and precious stones including their history Natural and commercial.djvu/62

 extensive sale than brilliants with. all their captivating beauty. In many operations of art they are indispensible; the fine Cameo and Intaglio owe their perfection to the diamond, with which alone they can be engraved. The beauty of the Onyx would yet remain dormant, had not the unrivalled power of the diamond been called forth to the artist's assistance, The carnelian, the agate, or Cairn-Gorm cannot be engraved by any other substance; every crestor letter cut on hard stone, is indebted to the diamond—This is not all, for without it blocks of crystal could not be cut into slices for spectacles—agate for snuff-boxes, &c.

the breaking of Diamonds, bits, shivers, an eighth of an inch long, sometimes occur, which if properly proportioned are in demand and used for drilling holes in glass, china, &c.