Color

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Doos 12:27, 13 August 2006 (PDT)

Hue

Color Code Name
R red
oR orangy red
RO/OR red-orange or orange-red
rO reddish orange
O orange
yO yellowish orange
oY orangy yellow
Y yellow
gY greenish yellow
YG/GY yellow-green or green-yellow
styG strongly yellowish green
yG yellowish green
slyG slightly yellowish green
G green
vslbG very slightly bluish green
bG bluish green
vstbG very strongly bluish
GB/BG green-blue or blue-green
vstgB very strongly greenish blue
vslgB very slightly greenish blue
B blue
vB violetish blue
bV bluish violet
V violet
vP* violetish purple*
P purple
rP reddish purple
RP/PR red-purple or purple-red
stpR strongly purplish red
slpR slightly purplish red
R red
Pk pink (exception)
Brn brown (exception)
*This was changed from bP (bluish purple)

Causes of color

The causes of color can be divided into 4 different theories:

  1. The Crystal Field Theory
    • Transition metal compounds (Malachite, Almandine)
    • Transition metal impurities (Emerald, Citrine, Jade)
    • Color centers (Amethyst, Maxixe-beryl)
  2. The Molecular Orbital Theory
    • Charge transfer (Sapphire, Iolite)
    • Organic coloration (Amber, Coral)
  3. The Band Theory
    • Conductors (Copper, Silver, Iron)
    • Semi-conductors (Galena)
    • Doped semi-conductors (Diamond)
  4. The Physical Properties Theory
    • Dispersion (Fire in Diamond)
    • Scattering (Moonstone, Cat's eyes, Stars)
    • Interference (Iridescence, Opal)
    • Diffraction (Opal)