Color Wheel in Gemology


Color Wheel in Gemology

Color Wheel and Color Mixes

Color wheels are very common in almost any type of painting and/or artwork, (just plain old paint for your house too, you have probably seen them at your local hardware store) and are used to help the artist learn what different colors will become when mixed together. As a matter of fact making your own color wheels (there are quite a few types) is usually an exercise that the new artist has to preform in class when starting to paint.

I have never understood why color wheels are so over looked in faceting colored stones, but I have never heard anybody discuss them. It is too bad because they are a tremendous help for deciphering color and color mixes for a new cutter.

In other words, if you have a piece of Tourmaline with a yellow axis and a green axis, what will the finished stone look like? A color wheel will give you a good general idea, look below and you can see what this combination will create. Of course faceted stones are optically different than paint on paper, but you will be surprised at how accurate a color wheel can be.

Below is a standard color wheel (primary colors) and a wheel of basic mixes. Take a close look at them, notice that as the colors get near the center of the wheel that they are darker (top). Basically the colors are the same mixes, but there is a black component being added in the the mixes for tone. The outer ring is a tint, or basically white is added.

Treat the black and tint components like the secondary (the one you are not cutting for) color axis (“c” on Tourmaline that is dark or clear) on the piece of rough you are looking at. Look below at the mixing chart to see how the colors of your piece of rough will mix.

Standard Color Wheel (primary colors)

What are complimentary colors? On a standard color wheel they are the colors opposite each other (red/green, yellow/blue). They look good together and compliment each other. I have books that list several different definitions for complementary colors. But…

What we are looking for in faceting are colors that compliment each (but not necessarily complementary colors) other when mixed. In other words colors that mix well together to create another pleasing color.

Note: Be aware that depending on the color wheels, where, and the context, the definition maybe completely different.

Look at the chart and the mixes in the center. This chart is primaries, which means they are colors that can be mixed to make other colors (like red and yellow make orange) but you cannot mix colors to make them, they are “Primaries”.

However, it is important to note that mixing colors that are not next to each other will often result in a muddy dull color. For example, if you mix red and green you are going to get a brown color, not desirable in a color stone (although used in painting).

It’s a good idea, that you know what colors will mix well together. There are a lot of other types of color charts and I recommend that you go to your local art store and at least look through them.

Here is a couple of other articles that will also help you with color, and determining what to do with a piece of rough.

How to use a Dichroscope

How do I cut a stone with different colors on different axis’s?

When you are buying faceting rough, you want to know if the color(s) on the axis’s of that Tourmaline or Sapphire will mix and make a nice colored finished stone. If not, then you will need to try and minimize one of the colors and maximize the other color when cutting because it will muddy and/or darken your stone. Sometimes one color is just more desirable than the other, easier to sell or will bring a better price. A color wheel will help you get a good idea of what the colors will mix like and help you decide on what design to cut.

I recommend that you go to an art store and purchase a good quality set of color wheels and/or charts. They will help you learn color. That is really what the hobby of faceting is all about in the end, color and brilliance.

Gram Faceting Archive of Information
This edited version of an article by the late Jeff Graham is part of a special archived informational series from Gram Faceting. Used with permission.