230 Precious Nephrite, Chinese Yu, $c. 



letters, names, and the figures of animals, &c. In all these 

 cases the arrangement noticed by Dr. Mac Culloch may be 

 observed ; and wherever an angle occurs, the convergence of 

 the crystals is very striking and beautiful. — Journal qf' Science. 



PRECIOUS NEPHRITE, CHINESE YU, &C. 



The Tcyouptsing, called also the modyoothwa by the Burmese, 

 and yee-shulou-tse by the Chinese, of which Dr. Abel's paper 

 gives some account, is said to be highly prized by the Bur- 

 mese, and to form a principal article of export from the Mo- 

 gaon country. It is stated that large prices are given for large 

 specimens, but that the purchasers run considerable risk, as 

 the precious part must be sought for in the centre of the stone, 

 and is frequently sought for in vain. The specimen which 

 Dr. Abel examined he describes as being of a dark green, 

 mottled or veined with a lighter green colour ; of a triangular 

 pyramidal form, of a polished surface, and as weighing 

 79 pounds 4 ounces troy. Whether this be the natural aspect of 

 the mineral, or has been produced by art, Dr. Abel does 

 not decide. From several experiments, he found its average 

 specific gravity to be 3*03. It resisted the action of the 

 blowpipe, excepting that it became white and brittle ; when 

 mixed with borax, and subjected to a strong heat, its 

 colouring matter formed a hard green glass with the flux, 

 whilst its substance formed a white enamel. The stone felt 

 greasy, and was broken with extreme difficulty. Its fragments 

 were very translucent on the edges. From its exterior 

 characters, Dr. Abel was disposed to class it with nephrite, 

 and considers it to be the oriental jade of mineralogists. A 

 subsequent analysis of the stone, however, has satisfied him 

 that whilst it is the mineral described under the latter name, 

 it is, in fact, distinguished both from nephrite and prehnite, 

 with the latter of which it has some analogy, by distinct che- 

 mical characters. He finds it composed of silica, lime, alumina, 

 iron, manganese, and chrome, and suspects the existence of 

 one or both of the fixed alkalis, but has not yet determined 

 the point to his satisfaction. From nephrite he states this 

 stone to differ in its proportion of silica, and in containing 

 very little or no magnesia, and resembles it in the presence of 

 chrome ; from prehnite it differs in its much smaller propor- 

 tion of alumina, and in the presence of chrome and manga- 

 nese, but resembles it in the proportions of silica and lime. 

 With Saussure's analysis of oriental nephrite it agrees in its 

 general constituent character, but differs from it in the propor- 

 tion of ingredients and in the presence of chrome; whether it 

 will also be found to agree with it in the presence of potass 



and 



