pert
and his recourse to a scientific test; the hardness of the ruby would
of course decide it. In its two-colour character, the tourmaline
resembles the ruby but surpasses it; the colour of the tourmaline is
not so deep nor is it so lustrous as the ruby's, but it is frequently
more transparent. While some red tourmaline resembles spinel, the
latter is singly refractive and has a yellow tint. Red topaz is harder
and of greater specific gravity than red tourmaline. The two colours of
the topaz are red and yellow while the tourmaline's are rose and dark
red. Sapphire is harder than tourmaline and clear blue, while
tourmaline is greenish blue. Aquamarine is a water blue and is harder
than tourmaline, but is of a lower specific gravity. The several other
colour varieties of tourmaline bear sometimes a strong resemblance to
other stones, but are easily distinguished by the expert, .usually
without further test than the employment of the dichroiscope.
Tourmaline has sometimes been confounded with some of the fine green
diopsides found in New York State.
Digging
for tourmalines, at least in one locality, offers the fascination that,
in some form, seems always present in the mineral industries. One of
the earlier sources of supply
