Carat Weight
The size of a diamond is an actual measurement of mass. A 1 carat diamond is equal to 200 milligrams.
There is no standard width, height or depth
for polished diamonds.
Because of this, many diamonds are cut
to maximize their weight and not their brilliance
(beware of buying a diamond solely based on weight). Jewelers use a point system
when speaking of a diamond's weight
100 points is equal to 1 carat.
Diamonds can weigh 1 point or 73 points
but pay particular attention to ½ carats (.50 points)
¾ cts (.75 points) and 1 carats (100 points.)
The price jumps in size
generally take place every 25 points.
Finally, different shapes of diamonds
look different for their size
because of the way they carry their weight.
For instance, a round brilliant cut diamond
carries the majority of its weight on the top
like an umbrella
whereas emerald cuts have a lot of their weight
in the pavilion (the lower portion of the stone).
When viewed from the top
the round cut will look bigger
than the emerald cut
even though they weigh the same.
A well cut 1 carat round brilliant diamond is about the size of the eraser on top of a brand new pencil. (6.5mm)