356 SYSTEMATIC DESCRIPTION OF PRECIOUS STONES 



Jocality being on the Rossrucken opposite the Berlin Hut in the Zemmgrund. They ai-e 

 first quarried and then freed from the mother-rock by grinding against each other in a 

 rotating barrel. The majority are sent to Bohemia, where, as we shall see presently, an 

 important garnet-cutting industry has been developed. To this country are sent garnets 

 from all parts of the world, and these, together with the stones which actually occur in the 

 country, are cut and used in the fashioning of various articles of jewellery. Most of the 

 garnets found in Bohemia, however, belong not to the variety known as almandine but to 

 that known as pyrope. Almandine of gem- quality is nevertheless found in Bohemia, 

 especially in the alluvial ground in the neighbourhood of Kuttenberg and Kollin, such 

 stones being known as " Kollin garnets." The occuri-ence of almandine here, as elsewhere 

 in Eui"ope, is unimportant. Other European localities for almandine which may be 

 mentioned are Mittelwald, in the Rohoznabach of Hungary, where crystals of considerable 

 size are sometimes found, and Alicante in Spain. 



PYROPE. 



Pyrope, or Bohemian garnet, is distinguished by its deep, rich, blood-red colour, which 

 has always an unmistakable tinge of yellow (Plate XIV., Figs. 5 and 6), sometimes even 

 verging upon hyacinth-red. Violet tints are never present in pyrope, and a garnet which 

 shows a tinge of this colour is almost certain to be almandine : in the case of other tints, 

 however, it is not possible to judge by colour alone. On account of the yellowish tint of 

 its colour, pyrope is included in the term vermeille garnet, while some practical jewellers 

 limit the application of the term to pyrope. It is highly probable that this stone was one 

 of those to which the name carbuncle was formerly given. Pyrope is very similar in colour 

 to some rubies, but, like almandine, it can be distinguished from this gem by the fact that 

 it is refracting and devoid of dichroism, as also by the fact that its specific gravity is less 

 than that of ruby, being only 3"7 to 3"8. The specific gravity of pyrope affords a sure 

 means whereby it may be distinguished from almandine when this cannot be done by colom- 

 alone, since almandine is considerably denser, having a specific gravity between -I'l and 4"3. 



Pyrope is essentially a magnesium-aluminium garnet, but of more complex composition 

 than the garnets hitherto considered. Besides magnesia it contains a not inconsiderable 

 amount of lime, ferrous oxide, manganous oxide, and chromous oxide, the latter of which 

 figures in analyses as chromic oxide. The magnesium-aluminium garnet is thus mixed with 

 calcium-, iron-, manganese-, and chromium-aluminium garnet. The colour, which is almost 

 invariably deep and rich, depends on the presence of small quantities of iron and manganese, 

 perhaps also of chromium. 



In contrast to almost all other garnets, pyrope scarcely ever occurs in distinct crystals. 

 The few which have as yet been found have the form of a cube with curved faces, a form 

 which is unique as far as other garnets are concerned. Pyrope occurs usually in irregular 

 grains, with a dull, rough surface, although that of a fresh conchoidal fracture is bright and 

 shining. The hardness (H = 7^) is slightly greater than that of quartz. The refraction is 

 greater than that of any other red garnet, the index of refraction for red light being 1-79 ; 

 the substance is perfectly isotropic and shows no anomalous double refraction. Pyrope 

 differs also from other red garnets in its behaviour before the blowpipe, since it fuses with 

 great difficulty ; it is possible to fuse only the thinnest splinters to a black, magnetic glass. 



Pyrope is usually perfectly clear and transparent so far as its dark colour allows. 

 That from Bohemia is all, without exception, of ideal purity. This absolute purity and 



