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(A) The iron-alumina garnet, having the formula 6FeO, 
This is the " precious " garnet, or almandine, sometimes called the "
Oriental " garnet; these stones are found in Great Britain, India, and
South America, and are deep red and transparent, of vitreous lustre.
They get up well, but certain varieties are so subject to defects in
their substance, brought about by pressure, volcanic action, and other
causes, some of which are not yet known, that their quality often
becomes much depreciated in consequence. This inferior variety of the
iron-alumina garnet is called the " common " garnet, and has little
lustre, being sometimes opaque. The perfect qualities, or almandine, as
described above, are favourite stones with jewellers, who mount great
quantities of them.
The second variety is the (B) lime-iron garnet, formula,
The chief of this class is the melanite, sometimes dull, yet often
vitreous ; it is mostly found in volcanic rocks, such as tuff ; this
variety is very popular with jewellers for mourning ornaments, for as
it is a beautiful velvet-black in colour and quite opaque, it is
pre-eminent for this purpose, being considerably less brittle than
jet, though heavier. Another variety is the " topazolite," both yellow
and green. The " aplome " is greenish-yellow, yellowish-green, brown,
and usually opaque. A further form of lime-iron garnet is the '
pyreneite," first found in the Pyrenees Mountains, hence its name.The (C) lime-chrome gurnets— 3SiOL,—the chief of which is " uwarowite." This is of a magnificent emerald green colour, translucent at edges
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