Once diamonds are mined, they are classified into one of over 2,000
categories based on size, shape and quality. It is during the
manufacturing stage that a very small percentage of diamonds receive
further treatment to improve their appearance. All known diamond
treatments must be disclosed to the consumer so that an informed
decision regarding a diamond purchase may be made.
2. Fracture Filling (Clarity Enhanced by Chemical
Infusion): Fracture filling is a process for filling
structural separations that occur naturally during the growth of a
diamond, or during the cutting process. It's purpose is to reduce
the visibility of surface reaching breaks or fractures in the
diamond which stand out in high relief compared to the rest of the
diamond. The break is filled with non-permanent filler with a
refractive index close to diamond, making it less noticeable. A
jeweler can identify the fracture filled diamond by looking for a
flash of color, or "flash effect". Fracture filled diamonds may
appear to be one to two clarity grades higher after enhancement. To
care properly for a fracture filled diamond, jewelers recommend
against soaking the diamond in a heated, ultrasonic cleaning
solution or using under a steamer. It is important to notify the
jeweler that the diamond has been fracture filled before they begin
any repair work on the piece, to ensure they use the appropriate
care.
A 10X loupe can be
used to detect some, but not all fillings. A
binocular microscope with good lighting may be
needed to detect some fillings. Ways to detect
fracture filled diamonds include looking for:
Color flashes.
Fracture filled diamonds show flashes of color in
the filled areas as the diamonds are rotated. These
flashes show the outline of the fracture or laser
drill hole.
Cloudy areas.
Filled diamonds can show white cloudy areas or
groups of tiny bubbles.
Bubbles.
Fracture-filled diamonds may show trapped bubbles,
which can be very tiny to quite large.
Some names for
fracture-treated diamonds include Yehuda treated
diamonds, Koss-treated diamonds, and Goldman Oved
treated diamonds.
3. Laser Drilling: Laser drilling is done
to remove or minimize the visibility of dark looking inclusions in
the diamond. A laser is used to create a microscopic tunnel from the
diamond surface to the inclusion therefore allowing light to reach
the inclusion. If further treatment is needed, an acid is injected
through the drill hole to "bleach" the inclusion. The clarity grade
of these diamonds is seldom changed after drilling, the original
inclusions are still there and the laser hole itself is another
inclusion. The positive benefit is that it does improve the
appearance of the diamond. Laser drilling is not considered
detrimental to the durability of the stone; therefore no special
requirements are necessary in caring for these diamonds.
4. Irradiation: In order to alter their
original color, diamonds can be irradiated using a nuclear reactor
and controlled heating known as "annealing". This improves the color
of the diamond, to make it appear the same shade as natural fancy
colored diamonds such as yellow, blue, green, brown, and pink
diamonds. Sophisticated equipment, such as an infrared spectrometer,
is needed to identify the origin of color. A jeweler's torch, at
several hundred degrees centigrade, used for standard repairs, may
affect the color of an irradiated diamond. It is, therefore,
important to inform the jeweler that the diamond has been irradiated
before they work on the piece.
