380 



GEMINI GEM-SCULPTURE. 



after a reign of s*-,ven years. He was succeeded by 

 his brother Hiero. 



GEMINI ; the Twins (n); one of the northern 

 signs, being the third sign of the zodiac, and the last 

 of tile spring signs. 



GEMS, or PRECIOUS STONES, are sometimes 

 found of regular shapes, and with a natural polish, 

 and sometimes of irregular shapes, and with a rough 

 coat. The first sort may be considered as of the 

 pebble kind, and are said to be found near the beds 

 of rivers, after great rains ; the others are found in 

 mines, and in the clefts of rocks. The gems of the 

 first were what the ancients most usually engraved 

 upon. These are commonly called intaglios; and 

 they are mostly of a long, oval figure, inclining to a 

 point at each end, convex as well on the engraved 

 face as on the others, with a ridge running from end 

 to end on the under side, which is hereby, as it were, 

 divided into two faces ; both which are also, though 

 not so distinctly, parted from the upper face by an- 

 other ridge running quite round the oval. The stone 

 most commonly found engraved is the beryl. The 

 next is the emerald ; and then the jacinth. The 

 chrysolite is but rarely found engraved, as are also 

 the crystal, or Oriental pebble, the garnet, and the 

 amethyst. 



The following is a general list of what are usually 

 called precious stones : the beryl, red, yellow, or 

 white ; emerald, green ; jacinth, of a deep, tawny 

 red ; chrysolite, of a light grass-green ; crystal, or 

 Oriental pebble, of a silvery white ; garnet, of a 

 deep red, claret colour ; amethyst, purple ; diamond, 

 white ; ruby, red, or crimson-coloured ; emerald, of 

 a deep green ; aqua marina, of a bluish, sea green, 

 like sea water ; topaz, of a ripe citron yellow ; sap- 

 phire, of a deep sky blue, or of a silver white ; cor- 

 nelian, red or white ; opal, white and changeable ; 

 vermilion stone, more tawny than the jacinth. All 

 these stones are more or less transparent. The fol- 

 lowing are all opaque: the cat's eye, brown; red 

 jasper, called also thick cornelian, of the colour of 

 red ochre ; jet, black ; agates of various sorts ; 

 blood-stone, green, veined, or spotted with red and 

 white ; onyx, consisting of different parallel strata, 

 mostly white and black; sardonyx, of several shades 

 of brown and white; agate-onyx, of two or more 

 strata of white, either opaque or transparent ; ala- 

 baster, different strata of white and yellow, like the 

 agate-onyx, but all opaque ; toad's eye, black ; tur- 

 quoise, of a yellowish blue inclining to green ; lapis 

 lazuli, of a fine deep blue. 



Of most of the species beforementioned, there are 

 some of an inferior class and beauty. These are 

 commonly called, by jewellers, Occidental stones. 

 They are mostly the produce of Europe, and found 

 in mines or stone quarries ; and are so named in op- 

 position to those of a higher class, which are always 

 accounted Oriental, and supposed to be only pro- 

 duced in the East. 



The onyx, sardonyx, agate-onyx, alabaster of two 

 colours or strata, as also certain shells of different 

 coats, were frequently engraved, by the ancients, in 

 relief ; and these sorts of engravings are commonly 

 called cameos. They also sometimes ingrafted a 

 head, or some other figure in relief, of gold, upon a 

 blood-stone. Besides which there are some antiques, 

 mostly cornelians, that are covered with a stratum of 

 white. This stratum has by some been looked upon 

 as natural, but it was really a sort of coat of enamel 

 that was laid on. The stones esteemed the best for 

 engraving upon, were the onyx and sardonyx ; and, 

 next to them, the beryl and the jacinth. The an- 

 cients engraved most of their stones, except the onyx 

 and the sardonyx, just as they were found ; their 

 natural polish excelling all that can be given by art ; 



but the beauty of the several species of onyx could 

 only be discovered by cutting. The merit of inta- 

 glios and cameos depends on their erudition, as it is 

 termed, or the goodness of the workmanship, and 

 the beauty of their polish. The antique Greek gems 

 are most esteemed ; and, next to them, the Roman 

 ones of the times of the higher empire. Lapidaries 

 employ a considerable quantity of diamond in powder, 

 which they use with steel instruments, to divide 

 pebbles and precious stones. The small pieces of 

 diamond, of which the powder is made, are worth 

 twenty-eight shillings a carat. The use of the dia- 

 mond in this way is very extensive. Had nature 

 withheld the diamond, the pebble, the agate, and a 

 variety of other stones, would have been of little 

 value, as no other substance is hard enough to ope- 

 rate upon them. In this way, rock crystal from 

 Brazil is divided into leaves, and ground and polished 

 with diamond dust for spectacles and other optical 

 instruments. 



Gems, Artificial. The great value of the precious 

 stones has led to artificial imitations of their colour 

 and lustre, by compositions in glass. In order to 

 approximate as near as possible to the brilliancy and 

 refractive power of native gems, a basis, called a 

 paste, is made from the finest flint glass, composed 

 of selected materials, combined in different propor- 

 tions, according to the preference of the manufac- 

 turer. This is mixed with metallic oxides capable 

 of producing the desired colour. A great number 

 of complex receipts are in use among manufacturers 

 of these articles. 



Gems, Imitation of Antique; a method of taking 

 the impressions and figures of antique gems, with 

 their engravings, in glass, of the colour of the ori- 

 ginal gem. Great care is necessary in the operation, 

 to take the impression of the gem in a very fine 

 earth, and to press down upon this a piece of proper 

 glass, softened or half melted at the fire, so that the 

 figures of the impression made in the earth may be 

 nicely and perfectly expressed upon the glass. The 

 yellowish tripoli has been found best adapted for this 

 purpose. 



GEM-SCULPTURE; the glyptic art, or litho- 

 glyptics ; the art of representing designs upon pre- 

 cious stones, either in raised work (cameos), or by 

 figures cut into or below the surface (intaglios). The 

 former method may have been practised at a very 

 early period, and probably had its origin with the 

 Babylonians, who worshipped the heavenly bodies, 

 and were accustomed to wear figured talismans, 

 which served as symbols of their influences. From 

 them, the custom of wearing engraved stones passed 

 to the Hebrews (Eichhorn, De Gemmis sculptis He- 

 braeorum, in the Comment. Soc. Gott. rec. vol. ii.). 

 According to others, this art originated in India. 

 The Egyptians cut the hardest kinds of stones. The 

 custom of wearing cut stones as seal rings appears 

 to have been general among the Greeks in the time 

 of Solon. One of the earliest artists in this branch, 

 of whom mention is made, is Mnesarchus, the father 

 of the philosopher Pythagoras, consequently a con- 

 temporary of that Theodoms of Samos, who engraved 

 the ring of Polycrates, of which such wonderful 

 stories are told by the ancients. These ancient 

 works were probably intaglios; the artist made use 

 of the lathe, the maxium, the ostracitis, the diamond 

 point, and diamond powder. Respecting the species 

 of stones chiefly used by the ancients, and the mysti- 

 cal powers attributed to the different kinds, see Bel- 

 lermann's Urim und Thummim, die altesten Gemmen 

 (Berlin, 1824). 



Whether the Egyptian scaralai, and the GKECO- 

 Etruscan imitations of them, are the most ancient 

 specimens of this interesting art, may be doubted on 



