Difference between revisions of "Color"

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====Mixing light - additive color mixing====
 
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===Lighting conditions===
 
===Lighting conditions===

Revision as of 11:24, 14 June 2007

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This section is currently under construction, do not edit until this message is gone
--Doos 07:43, 14 June 2007 (PDT)

Color is one of the most important (if not the most) factors that determine the beauty of gemstones.
While most other aspects in gemology are abstract and well defined, color is not. It is very subjective and the sensation of color differs from person to person as much as the visions of opponents in politics, religion or humor. To some even the absense of color is preferred and the beauty is perceived from the optical properties a gem might posses (as the brilliance in diamond or reflection from rutile needles in Kashmir sapphire).

Basic

Color

"a phenomenon of light (as red, brown, pink, or gray) or visual perception that enables one to differentiate otherwise identical objects"
Merriam-Webster Online Dictionary

As can be read from the above definition of color, to humans color is a perception constant. Merriam-Webster defines perception as "awareness of the elements of environment through physical sensation".

From this can be concluded that perception of color is a sensation that is different from person to person and is influenced by circumstances. People who are tired will most likely be less sensitive to color than those who are not. Photographers are well aware that objects have different colors in different lighting conditions. Furniture makers know that one should use only the fabric from the same dyed roll when covering a couch, as do tailors when making a suit as the circumstances in dying the fabric may chance rapidly, but subtle, when the dye-bath is cleaned or needs a new mix (causing a phenomenon named metamerism).

The same applies to gemstones. Gems look different under changing lighting conditions and a gemologist should be very aware of this. Blue sapphires look best during mornings and evening hours, while rubies are at their best behavior during high noon. Some gemstones even dramatically change their hue between daylight and incandecent light.

Causes of color

Mixing colors

Mixing paint - subtractive color mixing

Mixing light - additive color mixing

Special applications

Pointillism
Computer screens

Lighting conditions

Daylight

Skylight

Incandecent light

Sources

  • Ruby & Sapphire (1997) - Richard W. Hughes ISBN 0964509768