a 
Hopaz. 353 
2. External Characters. 
‘The structure of this mineral is always distinctly foliated 
at right angles to the axis of the prism, and often the folia are 
quite brilliant ; but more frequently little more so than felds 
it cleaves also in some specimens, but wit ulty and in- 
distinctly, in one or two other directions ion wa Bi incli- 
nation we have not been able to determine. The fracture is 
— glimmering, slightly conchoidal, and vitreous. Some- 
times imperfect prisms are partially united to ether ; not 
howaver! in the decided and delicate manner of the yenite ; 
in other cases the mineral consists of a solid i 
seven inches in diameter, geri however when ‘bro 
the foliated structure, parallel to the base of t 
risms, which are frequently irregularly divided by jocks 
Filed with thin layers of mica. Crystallized mica usually in- 
vests the crystals, its prisms penetrating the mineral under 
consideration to a considerable depth. The sides of several 
of the specimens which we have examined are longitudinally 
striated, The colour of ‘the best characterized specimens 
is honey yellow, sometimes limpid as quartz in small pieces 
and sometimes white. 08 is mostly only translucent, resem~ 
bling light-coloured felds 
mere friction it is not aheecectbly electric ; but on heat- 
ing it, it becomes decidedly so, and on applying the different 
extremities of a crystal to a suspended magnetic needle, it was 
found to possess — This needle was used merely as 
2 cape electrom 
The specifi c gents is is dnaancsineed by six trials with differ- 
ent specimens, is as follows : 
ist trial ~ ~ - - 3.44 © 
Gd OIE Se ee ae oer ae 
3d 6c - = = - 3.42 
Mean 3.45 
: Vor. Xx-No. Fo: 45 
