Diamond carat weight is the measurement of how much a diamond weighs. A metric “carat” is defined as 200 milligrams simply its 0.2 grams...
Diamond carat
weight is the measurement of how much a diamond weighs. A metric “carat” is
defined as 200 milligrams simply its 0.2 grams.
As nature would
have it, rough diamonds come in all shapes and sizes, as well as colors and
purities. The larger, whiter and cleaner the diamond, the more rare it is.
Accordingly, the cost per carat of a larger diamond of the same color, clarity
and cut will be higher than a smaller diamond. The price per carat of diamonds
rises proportionately with size. Keep in mind that per carat price gets
multiplied by the carat weight.
Diamonds are
more expensive per carat as each new carat weight category is reached. The
international diamond trade generally uses the following carat weight
categories.
¼ carat .23 to
.29
1/3 carat .30 to
.36
3/8 carat .37 to
.43
Light ½ carat
.44 to .49
½ carat .50 to
.69
¾ carat .70 to
.89
9/10 carat .90
to .99
1 carat 1.00 to
1.19
1 ¼ carat 1.20
to 1.49
1 ½ carat 1.50
to 1.99
2 carat 2.00 to
2.99
Size and perception
Sometimes in the
jewelry trade, the term “size” is used instead of carat weight. As diamonds
increase in weight, their size becomes less easy to perceive with the eye.
Diamonds with a shallow cut can have a greater diameter than diamonds with a
deeper cut and may appear larger than their actual weight. However, a diamond
with too shallow a cut will not pass light properly and will have less
brilliance than a diamond with a better balanced, well-proportioned cut. A
diamond with exceptional brilliance and fire can appear larger than its actual
weight.
Cut vs. Carat Weight
A well-cut and
polished diamond with precise symmetry will have more fire and brilliance and
give the impression that it is larger than a stone of equal weight but with a
lesser cut. In the U.S., the average diamond engagement ring sold today has a
weight of about 3/4 ct. A larger diamond with less brilliance will simply look
flat next to a smaller, well-cut and higher-performing stone. What people
notice most and what increases a diamond’s “wow” appeal is the way it transmits
light back to the viewer’s eye, and that’s affected more by the cut than any
other factor.
