MINERALOGY OF BLACK LAKE AREA. 
55 
It may be noted here that emerald-green chromiferous vesuvianite 
also occurs on the Monetnaja estate, Ekaterinburg, Urals. 
Pale yellow crystals also occur with the diopside in a manner similar 
to the above, but they are of a different habit (see Figure 21), The 
basal plane was absent in eight crystals which were measured, and was 
not observed on others which were examined with a lens. The prisms 
a and m have about the same development, sometimes one, sometimes 
Figure 19. Vesuvianite 
from the Montreal chrome 
pit ; illustrates the way in 
which some of the lilac 
crystals are striated. 
Figure 20. Vesuvianite 
from the Montreal 
chrome pit ; emerald-green 
crystal. 
the other, being the larger, and the edge between them is invariably 
truncated by narrow faces of the form f (210). The crystals are terminated 
by the unit pyramid p(lll) as dominant form, with s(311) somewhat 
smaller; faces belonging to other forms, as listed in the table below, are 
minute and not universally present. Although these and the emerald- 
green crystals are obviously later than the diopside with which they occur, 
