870 SYSTEMATIC DESCRIPTION OF I'RECIOUS STONES 



these stones tourmaline is distinguished by its specific gravity, which in the present variety 

 is 3"08 ; it therefore floats in pure methylene iodide, while the stones mentioned above all 

 sink. The dichroism of red tourmaline is not very pronounced; the two images seen in the 

 dichroscope vary in colour between pale rose and dark red, the former having sometimes a 

 tinge of yellow and the latter usually a tinge of violet. Other precious stones of a red shade 

 show different pairs of colours in the dichroscope, so that tourmaline may be distinguished 

 from them by means of this instrument. 



The principal locality for this beautiful red stone is in the Ekaterinburg district of the 

 Ural Mountains, namely, in the immediate and further vicinity of the village of 

 Mursinka. (Map, Fig. 63a.) It is mined here with amethyst, topaz, beryl, and other 

 variously coloured stones, and sent to be cut to the works at Ekaterinburg. It is on 

 account of its occurrence on the east side of the Urals that this variety of tourmaline has. 

 received the mineralogical name of siberite, while on account of its resemblance to the ruby 

 it is known to jewellers as " Siberian ruby." The village of Shaitanka, thirty miles south of 

 Mursinka and forty-five miles north of Ekaterinburg, deserves special mention as a locality for 

 red tourmaline. The mineral occurs here with albite, quartz, green mica, and red lithia-mica. 

 (lepidolite), in druses in a very coarse-grained granite, and is usually implanted upon the 

 albite and the lithia-mica ; the crystals are also found lying in a yellow clay which is. 

 probably a disintegration product of the granite. They are prismatic in habit and deeply 

 striated in the direction of their length. In colour they vary in shade between a paler or 

 darker cherry- or carmine-red and violet-blue ; tourmaline crystals of a pale olive-green or 

 of some shade of colour between pale liver-brown and dark brown or black are also found at 

 the same place. In nearly every case there is a slight difference in colour between the two. 

 ends of a crystal. At Sarapulskaya, seven and a half miles from Mursinka, groups of dark 

 cherry-red crystals, usually of small size and radiating from a common centre or arranged 

 in parallel, are found associated with tourmaline of other colours in a black earth, which 

 occurs, mixed with granite debris, at the foot of a hill of granite. 



There is also a sparing occurrence of red tourmaline in the district of Nerchinsk, in 

 Transbaikalia. 



The "Siberian "ruby " is specially prized in Russia on account of its national origin, 

 and is frequently worn as a gem ; the nearer its colour approaches the red of the ruby the 

 more valuable does the stone become. These " Siberian rubies " find less favour outside 

 Russia, at any rate in Europe. A finely coloured specimen of the stone is represented in 

 Plate XV., Fig. 6. 



The places mentioned above are the principal sources from whence red tourmaline is. 

 derived ; it occurs, however, at some other localities, but, as far as material of gem-quality 

 is concerned, only in small amount. It is found with ruby, sapphire, spinel, zircon, &c., ini 

 the gem-gravels of Ceylon and especially of Burma. 



Its distribution in Burma differs from that of the ruby, it being found near 

 Mainglon, twenty miles south-east of the town of Mogok, the centre of the ruby district.. 

 (See maps. Figs. 54 and 55.) Tourmalines, both red and black, are found as water- worn 

 pebbles in the sands of the Nampai valley, near Namseka village. The Chinese work the 

 deposits by excavating numerous small and shallow pits, and in the rainy season the stone 

 is obtained by washing. The whole of the material obtained in these ways is sent to China,, 

 where it is used in the making of buttons for the adornment of mandarins' caps, and is 

 probably held there in as high esteem as the ruby itself. Lower down the valley are- 

 numerous mines which are now quite abandoned. The Nampai stream drains a district of 

 gneirsose rocks, and it is, therefore, not improbable that the rubellite found in its sands and. 



