OVERTONE CHARTS (Continued…)

The following is a chart showing overtones certain gemstones are likely to have.

NAME OF GEMSTONE          OVERTONES          CLASSIFICATION

RHODOLITE GARNET
———————————————————————————————————–

[Red/Purple and
Red/Pink] +brown bad
+gray bad
+blue good
+orange bad

RUBY
———————————————————————————————————–

[Red] +blue very, very slight is good
and more is bad
+gray bad
+brown bad
+yellow bad
+pink slight can be acceptable
but not desirable; too
much and it is no longer
ruby, but sapphire.

SAPPHIRE
———————————————————————————————————–

[Blue] +purple any deviation from blue
is not desirable
can be acceptable but
not desirable
+brown bad
+green bad
+gray bad
[Yellow-Gold] +brown bad
+green bad
+orange good
[Pink] +blue good but not in excess
+gray bad
+brown bad
+yellow bad

SPESSARTITE GARNET
———————————————————————————————————–

[Orange] +red acceptable but not
Desirable
+yellow bad
+brown bad but stone may be
Acceptable
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OVERTONE CHARTS

The following is a chart showing overtones certain gemstones are likely to have.

NAME OF GEMSTONE          OVERTONES          CLASSIFICATION

ALEXANDRITE
———————————————————————————————————–

[Red phase]

+gray

bad

+brown

bad

+blue

acceptable

[Green phase]

+gray

bad

+brown

bad

+blue

acceptable

+yellow

undesirable

ANDALUSITE
———————————————————————————————————–

+red

good

+gray

bad

+pink

good

BERYL
———————————————————————————————————–

[Aquamarine]

+yellow

bad

+brown

bad

+gray

bad

[Emerald]

+blue

good except in excess

(Colombian “look”)

+yellow

good except in excess

(Russian “look”)

+brown

bad

+gray

bad

CHRYSOBERYL
———————————————————————————————————–

[Yellow]

+brown

undesirable

+gray

undesirable

[Pure Green]

+brown

undesirable

+gray

undesirable

[Chartreuse]

+brown

undesirable

+gray

undesirable

DIAMOND
———————————————————————————————————–

[Colorless]

+yellow

bad

+brown

bad

+gray

bad

+blue

good

+pink

good

[Canary]

Any derivation from Yellow is bad

[Pink]

Hot pink is created by a blue overtone but if overly prevalent turns the pink Into lavender.

[Blue]

Any derivation from blue is bad

GROSSULAR GARNET
———————————————————————————————————–

[Tsavorite]

Pure Green

+blue

Good optimum color

+yellow

bad

+brown

bad

+gray

bad

[Orange]

+yellow

bad

+brown

bad

+gray

bad

+red

good if not in excess

PERIDOT
———————————————————————————————————–

[Green]

+brown

bad

+gray

bad

SENSITIZATIZATION: THE LEXICON OF COLOR (Continued…)

MIXING COLORS

        Now that we have our own color lexicon, we can discuss the mixing of colors. By mixing the three primary colors … red, blue, and yellow, we get secondary colors. Red and blue make purple. Red and yellow make orange. Blue and yellow make green.

        Changing the value makes other name colors. Light red becomes pink. Artists make pink by adding white to red. Lavender is purple that has been similarly treated. Color balance can create name colors as well.
For instance, chartreuse is green with a great deal more yellow than blue. Chartreuse is simply a green that has so much more of one color than the other that it has both a distinct look and name.

        However, when we examine stone species and their colors, we quickly exhaust the name colors: red, yellow, blue, green, violet, orange, pink, and chartreuse. For the rest of the other colors we encounter we must make up names. For instance, when we say “Imperial topaz” we mean a stone composed of gold/yellow and orange with a hint of pink. “Aquamarine” stands for the name of both a beryl variety gemstone and the name of its own color. “Aquamarine” illustrates a very good example of how, in order to describe gem colors, it becomes necessary to find a common denominator in nature to point to and say — “That is the color.” “Aquamarine” has a connotation of a blue hue with just a hint of green, with a color value as well. The color value of aquamarine is not too dark. much as the sea is normally not too dark.

        The lesson of aquamarine helps to point out the type of thinking necessary when dealing with color in gems. While the gem market has assessed the general color of aquamarine, it will be your responsibility to examine each stone offered and decide upon its color.

*(From page 13) The GIA or Gemological Institute of America is a non-profit educational and research institution for gems and jewelry. It is currently located in Carlsbad, California. For further explanation see Education chapter page 58.