1 lie stones are cut en cabochon, and
at present are or very trifling value. An opaque and green variety of
the orthoclase, deriving its tint from an admixture of copper, comes
from Siberia, where it is called " amazon-stone;" but it is very little
known in England. The moon-stone is also known by the name of water or
Ceylon opal. At one period considerable value was attached to this
stone, the ancients employing it frequently in their works of art.
LAPIS LAZULI.
This beautifully-coloured stone has been employed from the earliest
times for various ornamental purposes. It is rarely found in crystals,
and when it does so occur the specimens are small, and of the rhombic
dodecahedron form. It has an imperfect dodecahedral cleavage,
