F
=
Flawless. The diamond shows no inclusions
or blemishes of any sort under 10X magnification
when observed by an experienced grader.
Note: Truly flawless or internally flawless
(F or IF on the GIA's grading scale)
diamonds are extremely rare.
IF
=
Internally Flawless. Diamond has no
inclusions when examined by an experienced
grader using 10X magnification, but
will have some minor blemishes.
VVS1,
VVS2 =
Very, Very slightly included. Diamond
contains minute inclusions that are
difficult even for experienced graders
to see under 10X magnification.
VS1,
VS2 =
Very slightly included. Diamond contains
minute inclusions such as small crystals,
clouds or feathers when observed with
effort under 10X magnification.
SI1,
SI2 =
Slightly included. Diamond contains
inclusions (clouds, included crystals,
knots, cavities, and feathers) that
are noticeable to an experienced grader
under 10X magnification.
I1,
I2, I3 =
Included. Diamond contains inclusions
(possibly large feathers or large included
crystals) that are obvious under 10X
magnification and may affect transparency
and brilliance.
The
term carat (ct) is a measurement of
weight, not size. There are five carats
to a gram. A 1 ct sapphire is smaller
in size than a 1 ct diamond because
it is heavier. There are 100 points
to a carat, so a 50 point diamond weighs
1/2 of a carat or 0.50 ct.
The
term spread refers to the size a diamond
appears to be, based on its diameter.
So a 0.90 ct stone with less depth might
look the same size as a perfectly cut
1.00 CT diamond, but has less brilliance
because it is cut shallow. |