COLOUR GUIDE 339
Pyrite | See p.66 | This gem naturally
occurs with a silver or pale brass-yellow
colouring. Pyrite has a metallic lustre
and is opaque.Petalite | See p.197 | Ranging from
colourless to pink or yellowish in
colour, petalite has a pearly lustre
and is transparent.Silver | See pp.42–43 | This popular
precious metal is silver-white, tarnishing
to black. It has a metallic lustre
and is opaque.Quartz (chatoyant) | See p.137 | Greyish
in colour, with a weak cat’s-eye effect,
the chatoyant quartz is translucent with
a greasy lustre.Bytownite | See p.173 | Yellowish or reddish
brown, bytownite is either transparent or
translucent and may have a vitreous
or dull lustre.Quartz (smoky) | See p.137 | Smoky quartz
is clear brown, varying from a light brown to
dark brown. It has a vitreous lustre and is
transparent to opaque.Quartz (aventurine) | See p.134 | This
quartz may be grey, green, red-brown, or
gold-brown. It is translucent or opaque
with a vitreous or waxy lustre.Jet | See pp.306–307 | Jet ranges
from dark brown to deep black. It has
an opaque appearance with a lustre
that may be waxy or dull.Obsidian | See p.323 | Translucent with a
vitreous lustre, obsidian ranges from black,
bluish, and mahogany, to golden or peacock,
among other hues.Chrysoberyl (Alexandrite) |
See pp.84–85 | Alexandrite can be
transparent or translucent with a vitreous
lustre. In gem form, it is pleochraic.Howlite | See p.127 | Occurring as
off-white, often with a grey or black
“spiderweb” matrix, howlite is opaque
with a vitreous or dull lustre.Onyx | See pp.154–55 | Black onyx is
black with white layers, which may appear
as straight colour bands. It has a waxy lustre
and is opaque.Tourmaline (schorl) | See pp.226–29 |
Schorl is black, blue-black, or brown-black.
It may be translucent or opaque, with a
vitreous or resinous lustre.Garnet (melanite) | See pp.258–63 | A
deep black in colour, this variety of garnet
has a vitreous or subadamantine lustre.
It is translucent or opaque.Pearl | See pp.292–95 | White,
cream, black, blue, yellow, green, or
pink varieties of pearl may be found. It
is opaque with a pearly lustre.Marble | See p.328 | This opaque stone
is found in a wide range of colours, with
violet, red, blue, or white veins. It can be
dull, pearly, or subvitreous.338-347_Colour-Index.indd 339 19/05/2016 12:55