37a SYSTEMATIC DESCRIPTION OF PRECIOUS STONES 



and J inch in thickness. It is specially abundant in the small Ribeirao da Tolha, ten leguas 

 from Chapada, and also in the district of Minas Novas in the State of Minas Geraes, where 

 it occurs with white and blue topaz. It is sometimes of a fine emerald-green colour, and 

 was indeed formerly thought to be emerald ; and until its identity with the far less costly 

 tourmaline was established, it was sought for with great eagerness. On account of this 

 similarity the stone is known to jewellers as " Brazilian emerald"; it is emblematic of the 

 priesthood in Brazil, and is much worn by priests as a ring-stone. 



Another important source is the gem-gravels of Ceylon, where tourmaline of a 

 yellowish-green colour, similar to that of chrysolite (peridot) occurs in abundance. Some 

 of these stones are yellowish-green only on one side, the other being white with a milky 

 opalescence. From the locality at which it occurs and its resemblance to chrysolite, this 

 stone is known to jewellers as " Ceylonese chrysolite," and also as " Ceylonese peridot." In 

 Ceylon, as in Brazil, it is accompanied by tourmaline of other colours, but the Ceylonese 

 stones are less deeply coloured than the Brazilian. The name tourmaline originated in 

 Ceylon, where turamali is the name used by Cingalese jewellers for hyacinth (zircon). 



The occurrence of tourmaline of a fine green colour in the United States has been 

 already mentioned. At Paris in Maine, and Chesterfield in Massachusetts, it is found not 

 only as the external shell of red crystals, but also as crystals which are green throughout, 

 and which, like the red stones, are often used as gems. The finest faceted stone cut from 

 the green tourmaline of Paris measures 25 millimetres across and is 18 millimetres 

 thick. 



It is possible for green tourmaline to be mistaken for other precious stones of the same 

 colour ; for example, for emerald, chrysolite, hiddenite, and demantoid. From all these 

 green tourmaline is distinguished by its specific gravity of 3'107, and by its strong dichroism, 

 a feature which is completely absent in demantoid and insignificant in the other stones. 



BLUE TOTJEMALINE or INDICOLITE (indigolite) is rare. It may be light or dark 

 in shade, and of a pure indigo-blue, a smalt-blue, or a blue more or less markedly tinged with 

 green. A faceted blue tourmaline is represented in Plate XV., Fig. 11. The colour is sometimes 

 not to be distinguished from that of sapphire, while other specimens may closely resemble 

 aquamarine in this respect. Indicolite may be distinguished from either of these stones by 

 its specific gravity, which is 3"16, and by its dichroism, this feature being specially prominent 

 in blue tourmaline. This variety occurs with green tourmaline, though in less abundance, 

 in Brazil, and because of this circumstance is known to jewellers as " Brazilian sapphire." A 

 few crystals suitable for cutting are found at Paris and other places in Maine, at Goshen in 

 Massachusetts, and elsewhere in North America; also at Mursinka in the Urals.- Fine 

 specimens of indicolite occur with green tourmaline, lepidolite, and quartz in the granite 

 south of Pahira, near Hazaribagh in Bengal. The largest crystals found here measure an 

 inch in length ; the central portion of the crystals is sometimes indigo-blue and the outer 

 layers green. Blue tourmaline in association with the yellow and brown varieties occurs also 

 with the sapphire of the Zanskar range in Kashmir. Everywhere, however, good transparent 

 tourmaline of a fine blue colour is rare and much more valuable than the green variety. 



BROWN TOURMALINE (dravite) still remains to be mentioned. This variety is 

 sometimes clear and transparent enough to be cut as a gem and is then a very pretty stone. 

 The colour varies from dark brown of different shades, through light brown to yellowish- or 

 reddish-brown. Beautiful transparent stones, both brown and yellow, accompany the green 

 tourmaline of Ceylon ; from this island comes the brown faceted stone represented in 

 Plate XV., Fig. 10. Among the brown crystals found embedded in mica-schist at Dobrowa, 

 near Unterdrauburg on the Drau in Carinthia, are some which are clear enough for cutting ; 



