Putting
on one side minor and accidental ingredients, although to these the
colours, absorption-bands, opalescence, etc., of the stone are due, the
percentage composition of zircon approaches.—
Spodumene.
Until
lately spodumene was not recognised as a stone which could be cut and
polished as a gem ; but a large importation from Brazil of brilliant
and transparent crystals of yellow spodumene led to some specimens
being cut and polished. The easy cleavage of the stone renders its
working and mounting difficult matters. Spodumene crystallizes in the
monoclinic system, and resembles in appearance the chrysoberyl. Its
hardness is 7, and its specific gravity 3'2. It contains in 100 parts :
with traces of soda, lime, potash, and water.
HlDDENITE.
This
beautiful green stone is transparent and of a brilliant green hue, not
unlike that of a rather yellowish green emerald. It is a variety of
spodumene, a mineral generally of a dull well-nigh opaque greyish or
creamy colour, but sometimes of a brilliant straw yellow and
transparent. Hiddenite rarely occurs in crystals sufficiently large for
cutting into gem-stones. A cut stone, however, nearly perfect, weighed
2-1/2 carats, and was sold for more than $125 a carat. It has been
found as yet in but one locality, Alexander county, North Carolina. It
was discovered by Mr. W. E. Hidden. Its hardness is 6|, and its
specific gravity 3-17.
Kunzite.
This newly-discovered variety of spodumene is remarkable for the very large size of the crystals in which it occurs, for the
