What
causes Diamond Inclusions or Blemishes?
Some
inclusions are caused by crystals of a foreign material
or another diamond crystal. Other inclusions are caused
by flaws in the structure of the diamond such as tiny cracks.
Blemishes are flaws on the exterior surface of a diamond.
These exterior blemishes are often the result of the cutting
and polishing process.
What
are the effects of Inclusions?
What
are the effects on the quality, clarity and value of a diamond?
-
Inclusions interfere with light passing through the
diamond and the stones ability to scatter and transmit
light
-
The fewer inclusions a diamond has the more brilliant,
rare and valuable it is
-
Diamonds which contain numerous inclusions are less
brilliant and less valuable
-
A diamond's resistance to fracture is decreased if cracks
are close to or breaking the surface of the diamond
-
Some inclusions can make a gemstone vulnerable to shattering
-
Only 20% of all diamonds mined have a clarity rating
high enough for the diamond to be considered appropriate
for use as a gemstone
-
Approximately 80% of all diamonds mined are relegated
to industrial use
What do Diamond Inclusions look like?
The vast majority of inclusions cannot be seen by the
human eye. They are located by a jeweller when viewed
from above under a 10X magnification.
-
Minute cracks can often appear whitish or cloudy
and could occasionally cause the diamond to split
Inclusions can be tiny colored spots including white,
black, red or green
Inclusions and Clarity
The clarity of a diamond describes the presence or absence
of inclusions within the diamond and any blemishes on
its surface. Diamond Clarity is one of the 4 C s of
diamond grading (Cut, Color, Clarity and Carat Weight).
The numbers, sizes, colors, locations and visibility
of inclusions and blemishes can effect the relative
clarity of a diamond. Systems have been developed to
grade clarity. Diamonds are graded for clarity on a
scale ranging from flawless to imperfect. For additional
information regarding diamond clarity please click the
following link:
Diamond Clarity
Different Types of Inclusions
There are basically two categories of inclusions found
in natural diamonds. Syngenetic inclusions formed at
the same time as the diamond and Epigenetic inclusions
formed afterwards. The names and descriptions of the
different types of inclusions and blemishes, which affect
a diamond's clarity to varying degrees are detailed
below:
Inclusion
-
Bearding - Stress hair-like lines sometimes occurring
during the cutting of a diamond
-
Carbon Spots: Black spots inside the clear diamond
-
Cavity - A large or deep opening in the diamond
-
Cleavage - A straight crack with no feathering
-
Cloud - A group of minute white inclusions resulting
in a milky or cloudy appearance
-
Feather - A separation due to either cleavage or fracture
which is often white and feathery in appearance
Internal graining
-
Irregular crystal growth which may appear milky, like
faint lines or streaks, or may be colored or reflective
-
Knot - An included diamond crystal which reaches the
surface of a polished diamond
-
Laser Lines - Vapor-like trails left behind when lasers
are used to remove dark inclusions from a diamond
-
Pinpoints - Minute spots internal to a diamond.
-
A cluster of pinpoints can form a cloud
Blemishes
-
Scratches - A fine white line, curved or straight
-
Fracture - A crack on the surface of the stone
-
Nicks - A chip near the girdle or a facet edge
-
Pits - A minute opening resembling a white dot
-
Polish lines - Minute lines caused during this process
Diamonds are
Forever...
An
Impartial Guide to Diamonds
Clouds - Feathers
- Knots - Cavities - Cleavage - Bearding - Internal graining - Blemishes
Polish lines - Grain boundaries - Scratches - Nicks - Pits
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