The use of diamonds as gemstones of decorative value
is the most familiar use to most people today, and
is also the earliest use, with decorative use of
diamonds stretching back into antiquity. The
dispersion of white light into a rainbow of colors,
known in the trade as fire, is the other
primary characteristic of gem diamonds, and has been
highly prized throughout history. Over time,
especially since around 1900, experts in the field
of
gemology have developed methods of
characterizing diamonds and other gemstones based on
the characteristics most important to their value as
a gem. Four characteristics, known informally as the
four Cs, are now commonly used as the basic
descriptors of diamonds: these are carat,
clarity, color, and cut.
Most gem diamonds are traded on the wholesale market based on single values for each of the four Cs. More detailed information from within each characteristic can then be used to determine actual market value for individual stones. Consumers who purchase individual diamonds are often advised to use the four Cs to pick the diamond that is "right" for them.
