are
of an iridescent green colour which resembles the eye of a fish ; which
often, in very thin lamina, becomes by reflection a pale rose colour.
This gem is remarkable for its brightness, which may compare equally with that of pearl and glass.
It is very easily worked, having three cleavages, and has double refraction.
Its cleavage is perfectly concave.
Being altogether destitute of electricity, it does not act on the magnetic needle.
When exposed to the action of the blow-pipe it melts into a transparent white glass.
Its specific weight is 2-5. The heat, 0.1861.
The analysis of adularla gives
