|
194 PRECIOUS STONES.
|
||
|
|
||
|
the United States, while those of inferior grade are purchased
in eastern Europe. Gold is most frequently used for mounting gems, though
silver is considered by some lapidaries the most appropriate for colorless varieties, since it preserves their transparency more effectually, and enhances their brilliancy. One method of mounting is by the close setting, with only the upper part visible, and another by the open setting, leaving the edge of the stone clear : the latter is preferred for the diamond. Engraved Diamonds. — It seems strange there should be
any difference of opinion on this subject among writers on precious stones, but such is the fact ; some who ought to know maintain that it neither has been nor can be engraved, while others support the opposite view. The historical evidence that engraved diamonds have been known, seems to be conclusive. Corsi, an Italian antiquary, says Ambrose Caradossa, in 1502, was the first to engrave the diamond, and accomplished a work of the kind for Pope Julius II. The discovery of the method has been ascribed by others to Trezzo, a celebrated Milanese artist, who executed several engravings upon this gem. His first attempt represented the coat-of-arms of the Emperor Charles V. ; then followed the portraits of Don Carlos, Mary Queen of England, Mary Queen of Scots, and the arms of Phillip II. of Spain, all the works of this engraver or some of his pupils. A number of intagli were cut on diamond by the Cinque-cento artists. According to Stosch, both Giovanni and Carlo Costanza, modern Italian artists, executed some fine portraits on the diamond, mentioned in the chapter on "Engraving on Precious Stones." Other instances could be cited, but they are not needed to prove what is so well known. Several engraved diamonds, the productions of the Costanzi, were stolen at the robbery of the Galleria della Gemma, in Florence, in i860. |
||
|
|
||