GARNET. 



AY) iSi, part of the lime being replaced by 



Ye, Mg, and part of the -trr bv Al. 



H. 7-5 to 8-0. S.G. 3-4184/ 



BB infusible alone : with borax yields a 

 fine chrome-green glass. 



Pyrope, also, comes under this head, 

 according to Rammelsberg. 



BB many of the Garnets are easily fu- 

 sible. 



Localities. Cornwall, in perfect detached 

 dodecahedrons in the Crown's Rock (green- 

 stone), at Botallack, in St. Just ; and near 

 Camborne, Jig. 206. On Dartmoor, in 

 Devonshire. Cumberland at Saddleback, 

 and near Keswick. Also in Ireland, Scot- 

 land, and various other countries, generally 

 in granite, dolomite, or mica-slate. 



The Garnet varies greatly in transparency, 

 fracture, and colour, but when the colours 

 are rich, and the stone is free from flaws, it 

 constitutes a valuable gem, which may be 

 distinguished by the following properties. 



The colour should be blood- or cherry- 

 red, on the one hand, often mixed more or 

 less with blue, so as to present various shades 

 of crimson, purple, and reddish violet ; and, 

 on the other hand, with yellow, so as to 

 form orange-red and hyacinth-brown. 



In size the stones vary from the smallest 

 pieces that can be worked to the size of a 

 nut. When above that size, they are scarcely 

 ever free from flaws, or sufficiently trans- 

 parent for the purposes of the Jeweller. 



The Garnets of commerce are procured 

 from Bohemia, Ceylon, Pegu, and Brazil. 

 By Jewellers they are classed as Syrian, 

 Bohemian, or Cingalese, rather from their 

 relative value and fineness than with any 

 reference to the country from which they 

 are supposed to have been brought. 



The most esteemed kinds are called Syrian 

 Garnets, not because they come from Syria, 

 but after Syrian, the capital of Pegvi, 

 and formerly the chief mart for the finest 

 Garnets. The colour of the Syrian Garnet 

 is violet-purple, in some rare instances rival- 

 ling that of the finest Oriental Amethyst, 

 from which it may be distinguished, how- 

 ever, by acquiring an orange tint by candle- 

 light. The Syrian Garnet may be also dis- 

 tinguished from all the other varieties of 

 Garnet in preserving its colour (even when 

 of considerable thickness, and unassisted by 

 foil), unmixed with the black tint which 

 usually obscures this gem. The Bohemian 

 Garnet is generally of a dull poppy-red 



GAY-LUSSITE. U9 



colour, with a ver}' perceptible hyacinth- 

 orange tint, when held between the eye and 

 the light. When the colour is a full 

 crimson, it is called Pyrope or Fire-Garnet, 

 a stone of considerable value, when perfect, 

 and of large size. 



The best manner of cutting Pyrope is en 

 cabochon, with one or two rows of small 

 facets round the girdle of the stone. The 

 colour appears more or less black when the 

 stone is cut in steps, but when cut en cabochon 

 the point on which the light falls displays a 

 briliant fire-red. 



Garnet is easily worked, and, when facet- 

 cut, is nearly always (on account of tiie 

 depth of its colour) formed into thin tables, 

 which are sometimes concave or hollowed 

 out on the under side. Cut stones of this 

 latter description, when sidlfully set with 

 bright silver foil, have often been sold for 

 rubies. 



The Garnet, after having long been out 

 of fashion, appears to be coming into favour 

 again. About a century and a half ago, a 

 fine set of Garnets Avas considered a mag- 

 nificent ornament for ladies of the highest 

 rank. 



The Garnet may be distinguished from 

 the Corundum or Spinel by its duller colo'.ir. 



Coarse Garnets, though of inferior hard- 

 ness to emery, are sometimes used as a sub- 

 stitute for it. When reduced to poAvder, they 

 afi"ord a material superior to sand for giving 

 a smooth surface to metal and stone-work, 

 preparatory to polishing, and for cutting- 

 gems. S 



The Carbunculus Garamanticus, or Gara- 

 mantine Carbuncle of the ancients (the 

 a.vd^oc^, of Theophrastus) was the true Garnet 

 of the moderns. 



Name. The word Garnet is derived from 

 the Low Latin name Garanatus, which was 

 given to the mineral from its red colour, 

 resembling that of the seed of the pome- 

 granate. 



Brit. Mus., Case 36. 



M. P. G. Horse -shoe Case, Nos. 880 to 

 904. Upper Gallery, Wall-case 1, No. 93. 



Garnsdokffite. a name for Pissophane, 

 from its occurrence at Garnsdorff", irear 

 Saalfeld. 



Gay - LussiTE, Boussingault. Oblique : 

 primary form an oblique rhombic prism. 

 Occurs in detached prisms, and aggregated 

 crystals disseminated in clay. The less 

 perfect of these bear a strong resemblance 

 to Selenite ; but the more perfect and smooth 

 have rather the aspect of Calcareous Spar, 

 L 3 



