10 



CATALOGUE OP THE 



/ _ /-- 110 Foliated native gold on quartz, Transylvania / — / — m 



W /../$—' 111 A capital specimen of native foliated, and moss-like gold, ; ; 



Transylvania 



/ /a _ 112 Black haematites iron ore, from Triers, with ensiform crys- , 



tallised manganese on the surface, an uncommonly fine - # • 

 specimen ^ % JjH 



J? ^2= ^ 113 A matchless specimen of brilliant gray crystalized cobalt, .. 



Hesse. The crystals are of most uncommon magnitude 

 j / _ 1 14 Two crystals of aqua marine, one very perfectly formed and j f £ 



having the apex complete, Siberia 

 *jCL-4^ - 115 A cut specimen of topazine crystal, Brasil 



11(3 A most beautiful and capital specimen of stalactitical iron, 

 the surface richly coloured, Germany 

 J? _ tfi . 117 Crystals of topaz in a quartzose matrix, extremely well 



p defined, Saxony 



& f — 118 A single crystal of the Saxon topaz, very large and fine 



J A - ll 9 Op a i in tne matrix 5- jf^f 



jtjijc * 120 A capital, and for beauty and magnitude unique, specimen of ' 



the true Avanturine, weighing near 5lb. This curious 

 article was found ill the ruins of the triumphal arch of 

 Jt^cfZd^sri Julius Caesar, in the valley of Suse in Piedmont, in !78S> 



\7 , by the Sieur Francis Ludwig, of Mayence, It takes a 1 



very high polish, and is much harder and infinitely more 

 beautiful than the stone commonly known by the same 

 name* 



% The artificial Avanturine has been known for ages, speci- 

 mens of it being frequently found among the antient ruins 

 /J'' £ of Rome. Some eminent mineralogists have qiiestioned the 



existence of such a beautiful stone as the natural Avantu- 

 rine ; but the folloiving respectable authorities put the 

 matter beyond a doubt. They are translated from the. 

 originals and addressed to Mons. Ludwig of Mayence., 

 from whom the specimen was purchased for two hundred 

 guineas. 



SIR, — " The Quartz Avanturine that you have been so 

 '- e obliging as to let me see, merits, by its beauty, the utmost 

 - ( attention of the amateurs. I have never seen one yet which 

 s< more resembles the artificial glass, known by the name of 

 f* Avanturine, I am, Sir, 



Your very obedient Servant. 

 Vienna, 12th May, 17QQ. J. Borne/* 



" I perfectly coincide with the sentiments of my 

 t* friend Mr. le Chevalier Borne, that it is a laminated ferrugi- 

 " nous quartz, of the carnelion colour, abundantly impregnated 

 with copper- coloured mica., which, by the intimate mixture 



