288 Professor Gmeliii's Analysis qf Diploite. 



Characteristic according to Mr Breithaupt. — Lustre vi- 

 treous, passing to pearly upon the most perfect cleavage. Co- 

 lour rose and peach-blossom red. Rhombic. Massive, and 

 coarsely disseminated. Has cleavages in two directions, the 

 one distinct, the other less so, forming with the former an 

 angle of about 95°. Hardness 6.5 to 7. Specific Gravity 2.72, 

 (according to Mr Brooke about 2.8.)* 



Relations before the Blow-pipe. — Before the blow-pipe it 

 loses its colour, becomes snow-white, swells up, and melts on 

 the edges to a little transparent mass, full of bubbles. With 

 salt of phosphorus, it melts to a clear glass, containing a skele- 

 ton of silica ; with borax, to a colourless glass. With soda, it 

 melts to a white glass, a little transparent, which, by an addi- 

 tional quantity of soda, becomes less fusible. Upon a plati- 

 num lamina, the manganese reaction appears. 



I shall only give the results of two analyses to which di- 

 ploite was subjected. 



102.162 98.777 



For the analysis with barytes 1.776 gr. and for that with 

 potash 0.815 gr. were expended. A particular analysis was 

 besides instituted to ascertain whether fluoric acid is an insre- 

 dient of diploite ; but, as not more than 0.2 gr. could be ex- 

 pended, the negative result, that has been obtained, cannot be 



considered as a decisive one. Perhaps the formula "• j- S +5AS, 



or ItS -f- 2CS + 15AS might represent the composition of 

 diploite. Hence the opinion of Mr Breithaupt, that diploite 

 is nearly related to feldspar and scapolite, is confirmed also by 

 chemical residts. 



* This is equivalent to 5.25 — 5.5 in the scale of Mobs, between Apatite 

 and Actynolite, but nearer the latter. — Ed. 



