334 SYSTEMATIC DESCRIPTION OF PRECIOUS STONES 



distinguished from them by the name Saxon topaz. This so-called " Schnecken topaz " was 

 at one time much admired and sought after ; the specimens of decorative art, now to be seen 

 in the " Green Vaults " at Dresden, bear witness both to the exceeding beauty of some of 

 these stones and to the favour in which they were at one time held. 



During the eighteenth century, certainly as far back as the year 1737, Schneckenstein 

 topaz was systematically mined and placed on the market. The stones were sorted into 

 three groups ; the largest and purest were referred to as ring-stones {Ringsteine), the next 

 quality as buckle or clasp-stones {Schnallensteine), and inferior stones as Karmusirgut. No 

 mining has been carried on here for a long period, and the terms just mentioned have long 

 since been forgotten in the locality. 



Brazil, where, as we have seen, are to be found diamond, beryl, and chrysoberyl, is no 

 less rich in topaz. All the colour-varieties of this mineral are found there in abimdance, 

 especially in the State of Minas Geraes, other Brazilian localities being of small importance 

 compared with this. 



Brazilian topaz is either blue, yellow, or colourless. The colourless and blue varieties 

 always occur together as water-worn pebbles in secondary deposits ; yellow topaz, on the 

 other hand, is met with only in its primary situation. Moreover, the localities for the 

 colourless and blue and for the yellow varieties are widely separated. 



White and blue topaz has already been mentioned as occurring in the district of 

 Diamantina in association with diamond, and with beryl and chrysoberyl in the district ot 

 Minas Novas. This latter, which is known also as the district of Arrassuahy, is the most 

 important locality for the blue and white varieties of topaz. It is situated in the north- 

 east of the State of Minas Geraes, to the north-east of Diamantina, in the middle reaches 

 of the diamond-bearing river Rio Jequetinhonha, known in its lower course as the Rio 

 Belmonte, and to the south of this river. The gem-bearing deposits of this region extend 

 over the plateau between the Rio Jequetinhonha and the Rio Arrassuahy towards the south 

 and east as far as the Serra das Esmeraldas, a part of the Serra do Espinha^o. The precious 

 stones which occur here are, or at least were at one time, of great commercial importance. 

 The colourless topaz pebbles found here are known as "pingos d'agoa," or as "minas novas,'" 

 after the district, while the blue stones are known in Brazil as " safiras "' (that is to say, 

 sapphires). In association with these two varieties of topaz are found garnet, chrysoberyl, 

 aquamarine, rock-crystal, red quartz, amethyst, transparent spodumene, andalusite, and 

 green tourmaline. The latter mineral, on account of its colour, was supposed to be 

 emerald, hence the name Sen-a das Esmeraldas given to a mountain range in the 

 neighbourhood. The principal localities are in the wooded and inaccessible wilds 

 between the Rio Jequetinhonha and the three source- streams of the Rio S. Matheus, 

 usually known as the Rio Americanas. Topaz pebbles are found loose in the debris of 

 these streams, as well as in others which flow into the Jequetinhonha ; one of these, the 

 Ribeirao Calhao, is well known and has been already mentioned as a locality for 

 chrysoberyl. Workings for precious stones are reported to be in existence also on the 

 upper Rio Piauhy. 



Topaz is extremely abundant here, much more so than any of the other precious 

 stones mentioned. It occurs as broken fragments, or more frequently as rounded, water- 

 worn pebbles, the size of which varies between that of a pea and that of a chestnut. 

 Larger fragments or pebbles the size of a man's fist or head, and weighing several pounds, 

 have been met with, but are rare. The best quality of white topaz is said to be found in 

 the Rio Utinga, but the "pingos d'agoa" are by no means confined to the bed of this 

 river. The blue topaz is sometimes dark in shade, and sometimes pale or almost colourless ; 



