30 



JADEITE FROM BURMA— FARBINGTON. 



contain it, until a suitable piece is found. This is then laid aside to be 

 sold to the caravans which come to the mines for this purpose from 

 China and other countries, or it is worked by the native artisans. 



These latter cut the bowlders with a saw made of a bow of bamboo, 

 strung with a steel wire composed of finer wires twisted together. Keep- 

 ing the stone wet by water dripping from above, they sit down before 

 it and with this primitive tool saw away day after day till they have 

 reduced it to the desired shape. This process seems painful and 

 laborious enough, but before the use of steel was known, its difficulties 

 must have been far greater. 



The specimens examined had in general a pure white color, but con- 

 tained occasional spots of light green. For the purpose of analysis^ 

 only the wliite i)ortions were used. 



The analysis gave the following results: 



SiOj . . 

 AljOj . 

 FcjOa . 

 CaO.. 

 MgO . 

 NajO. 

 Ign . . . 



58. 9& 



24. 77 



.32 



. 14 



tr. 



14.51 



J.14 



II. 



59. 45 



24.32 



.36 



.22 



tr. 



14.42 



1.15 



Mean. 



59.22 



24.55 



.34 



.18 



14.40 

 1.14 



99. 



99.92 



Katio. 



.987 

 .241 1 

 .002 ' 



.003: 



.233! 



4 

 0.98 



.0.96 



Theory for 

 NaAl 

 (SiOs)^ 



59.4 

 25.2 



15.4 



The state of oxidation of the iron was not determined. Manganese 

 was probably i)resent in minute quantity, as indicated by the color of 

 the sodium carbonate fusion, but it was impossible to precipitate a 

 weighable amount. The analysis shows no essential differences from 

 those made of similar material by Schoetensack* and Damour,t except 

 in the fact that the percentages of OaO and MgO are very small. As 

 neither of these molecules Avould be present in a typical j ad eite, the 

 material analyzed may therefore be considered as unusually pure, and 

 the close approximation of the ratios to those recpiired by the formula 

 tends to confirm the correctness of the latter. 



Macroscopically the jadeite is subtransliicent, exhibits a homogene- 

 ous, fine grained texture, and is very tough. Under the microscope it 

 is seen to be made up of small irregular granules and flat, parallel fibers 

 closely interwoven. The granules rarely exceed 0.06 mm. in diameter 

 and the fibers have an average width of only 0.05 mm. with a varying 

 length of from 0.15 mm. to 0.(1 mm. In this f^nenessof grain the material 

 differs from the INIonghoung jadeite described by Schoetensack, as he 

 states that to consist of "grobkornigen und auch langgezogenen Lara- 

 ellen." The absence of distinct crystal forms renders optical orienta- 



* Die Nephritoicle cles mineralogischen uucl des ethnographisch-priiehistoriechen 

 Museums der Universitiit Freiburg im Breisgau. Inaug. Dis., Berlin, 1885. 

 t Bull. Soc. Mill., IV, 1881, 157. 



