Adamas -- The origin of diamond, Greek word meaning
Appraisal -- The document that contains the official valuation of
a diamond or piece of jewelry, made a certified gemologist and
expert in the field of metals and diamonds.
Asscher -- type of gem cut that features a square stone with cut
corners, named after the world-renowned cutter Joseph Asscher.
Baguette -- A type of gem cut that features a rectangular step cut
gemstone, generally used to complement larger gemstones like
diamonds. Baguette cut stones can be straight and rectangular, or
tapered and trapezoidal.
Bezel -- A type of gemstone setting where the
stone secured by a metal rim that covers it at the girdle. This type
of setting is very advantageous for diamonds as it allows the
diamond to sparkle brightly while being held securely and protected
by the setting.
Black Diamond -- A fancy color diamond. These diamonds are saturated
with graphite inclusions that give it its black appearance.
Brilliant Cut -- A round cut diamond cut that is designed with
triangular-shaped facets. A brilliant cut gemstone generally has 57
facets that point toward the outer points of the stone, increasing
their sparkling abilities.
Canary -- A fancy color diamond. These diamonds come in an
intense or vivid yellow color.
Carat (ct.) -- Metric unit of measurement to weigh diamonds.
One carat equals .2 grams or .007 ounces.
Certification -- Issued by independent gemological
laboratories, these documents detail the vital characteristics like
carat, color, clarity, and cut of the diamonds and gemstones that
pass through their laboratories.
Channel -- A type of gemstone setting where several gemstones
are mounted in a grooved channel. The stones are secured together in
the channel without metal separating each stone.
Clarity -- The visible internal and external characteristics
of a diamond or other gemstone when viewed under 10x magnification.
Color -- The rating of a diamond’s coloring when compared to
a master stone or stones.
Crown -- The portion of a gemstone above the girdle,
generally largely visible in most stone settings and mountings.
Crown Angle -- The relationship between the crown of a
gemstone and the girdle of a gemstone that is measured in degrees.
Culet -- The polished facet of a gemstone at the bottom of
Cushion -- A type of gem cut that features a square cut
gemstone with rounded corners.
Cut -- This term describes the shape of a gemstone, as well
as the shape and quality of the diamond cut.
Cut Grade -- The GIA rating that describes a diamond or
gemstone’s polish, symmetry, weight ratio, brightness,
scintillation, and fire quality.
Depth -- The measurement of a gemstone or diamond that describes the
distance from the top of the crown to the bottom of the pavilion.
Depth Percentage -- This information can be found by dividing the
width by the depth of the gemstone.
Diamond -- A precious gemstone, composed entirely out of carbon. It is
one of the hardest substances known to man, and is used in industry
as well as in jewelry.
Dispersion -- The amount of light that shoots through the top of a
diamond and displays a color spectrum.
Emerald -- A type of gem cut that mimics the way emerald
gemstones are cut. This rectangular cut, is shorter in length than a
proper rectangular cut.
Facet -- A flat, polished surface of a gemstone that
should enhance the sparkle or brilliance of the stone.
Fancy Color -- Colored diamonds that are of higher values
than other diamonds.
Fancy Shapes -- Any type of gemstone cut that isn’t round.
Finish -- Term that describes the polish and symmetry of a
gemstone or diamond, as well as the quality of these
Fire -- The brilliance and amount of light that enters a
diamond and is returned to the viewer.
Fluorescence -- A quality of a diamond when exposed to
ultra-violet light. When a diamond is exposed to UV light, it often
glows with a blue hue.
Gemological Institute of America (GIA) -- A nonprofit
teaching institute considered the standard-bearer in the grading of
diamonds and colored gemstones.
Girdle -- The outer edge of a cut stone, the dividing line
between the crown and the pavilion. Sometimes the girdle is polished
and sometimes it is unpolished. Ideally the width of the girdle
should be even and proportional to the cut of the stone.
Grain: 1/4 of a carat; 1ct = 4 grains
Grams: unit of weight measurement; used for gold
Growth or grain lines -- These can be considered internal
flaws, and can often be seen only by rotating the diamond very
slowly. They can appear and disappear almost instantaneously. They
appear as small lines or planes within the diamond.
Gypsy setting -- The Gypsy setting is predominantly used
for men's jewelry. The band is one continuous piece that gets
thicker at the top. The top is dome shaped and the stone is inserted
in the middle.
Hardness -- Resistance a material offers to scratching or
abrasion. Generally measured using the MOHS scale.
Heart -- A type of gem cut that is shaped like a
pear cut gemstone, with two rounded edges at the top instead of one
to create the image of a heart.
Hearts and Arrows: A quality of ideal cut
symmetrical diamonds. When viewed face up the gemstone will appear
to exude arrows and when viewed face down the gemstone will appear
to exude hearts. This characteristic can only be viewed for certain
under a microscope.
Ideal Cut -- A high quality style of diamond cut that are of
exceptional makes with high light performance.
Inclusion -- "Internal characteristics" apparent to a
trained or professional eye at 10x magnification. Inclusions can be
bubbles, crystals, carbon spots, feathers, clouds, pinpoints, or
other impurities, or even cracks and abrasions. They are what make a
diamond so unique, as a fingerprint does for a person.
Intensity -- This term describes a type of grading for fancy color
diamonds. The higher the color concentration in a fancy color
diamond, the higher the intensity which leads to the diamond being a
Illusion setting -- This setting is more intricate than
others in that it surrounds the stone to make it appear larger.
Kimberlite: The volcanic rock formations where diamonds are found.
Laboratory: facility equipped with scientific
tools to verify natural diamonds and grade their characteristics
Laser Inscription: caption on diamond girdle
used mostly for identification
Loupe -- Any small magnifying glass mounted for hand use,
to hold up to the eye socket or attach to a pair of glasses.
Luster -- The hue and depth of reflection from pearls,
opals or other opaque stones.
Make -- This term refers to the craftsmanship of a diamond’s cut and
Marquise shape -- A double-pointed, boat-shaped stone that
is long and thin with gently curved sides coming to a point on
either end. Marquise is part of the brilliant-cut family; ideally
cut it has 58 facets.
Master Stone -- A diamond of predetermined color that is used to
grade the color of all other diamonds by comparison in diamond
markets and laboratories around the world.
Measurements -- The dimensions of a gemstone, generally expressed in
millimeters in this order: width 1 x width 2 x depth.
Mixed-cut -- This cut has both step-cut and brilliant-cut
facets. Mixed cuts combine the beauty of the emerald cut with the
sparkle of the brilliant cut.
MOHS Scale -- A scale of hardness with numbers from one to
ten assigned to ten minerals of increasing hardness from talc to
-- Small, usually round diamonds less than .10 carats in size.
Natural -- A diamond characteristic that is part of the
surface of a polished diamond that was not cut or polished during
the cutting process.
Oiling -- This technique is commonly used on emeralds. The
purpose of this technique is for the oil to fill the fine cracks
that weaken the green color. The oil fills the cracks making them
"disappear" and thereby improving the color.
Oval -- A type of gem cut that is shaped like an oval, often described
as an elongated round cut gemstone.
Pave -- Multiple small diamonds set in two or more rows, as closely
together as possible.
Pavilion -- The part of a faceted gemstone below the girdle.
Pavilion Angle -- The degree of the relationship between the pavilion
and girdle of a gemstone.
Pear -- A type of gem cut that is a combination of brilliant round and
marquise cuts that resembles a tear drop.
Pinpoint -- An inclusion within a diamond. A gathering of
pinpoints is called a "cluster" or "cloud." A cloud or cluster can
appear as a hazy area in the diamond, a pinpoint appears as a dot.
Point -- Term meaning one-hundredth of a carat --
approximately the size of one-half a grain of sand.
Polish -- Indicates the care taken by the cutter in
shaping and faceting the rough stone into a finished and polished
Poor cut -- A poorly cut diamond can be either cut too
deep or too shallow. A deep or shallow cut diamond will lose or leak
light through the side or bottom. This results in less brilliance
Pressure -- A setting type that holds multiple gemstones in a
mounting with pressure.
Princess -- A type of gem cut that is a square cut gemstone with 90
degree angled corners.
Prong -- A type of gemstone setting that uses fine metal prongs to
hold the gemstone in place.
Proportion -- The proportions of a diamond are very
important, so that the maximum amount of light be reflected off and
out of a stone. Proportion is the relationship between the angles of
the facets of the crown and pavilion.
Radiant cut -- A rectangular or square shaped diamond with
step-cut and scissor-cut on the crown, and a brilliant-cut on the
Reflection -- Immediate reflection of light given
off by a diamond's surface.
Refraction -- The bending of light rays as they pass
through a diamond or gemstone.
Rhodium -- A method used to give metal a white color. Gold and
platinum can be dipped in this protective alloy to prevent
tarnishing and enhance existing white color in platinum, or change
yellow gold into white gold.
Rough -- any uncut diamond
Round -- A type of gem cut where the gemstone is cut to be perfectly
round, but lacks the facets of a brilliant cut gemstone.
Scintillation -- When light reflects from a diamond, the
sparkling flashes that come from the facets of the gem are known as
Shallow cut -- When a diamond is cut too shallow, it will
lose or leak light through the side or bottom. This results in less
brilliance and value.
Shape -- Form or appearance of a diamond; i.e.: whether
the diamond is round, triangular, square, marquise, pear, oval or
Solitaire -- A ring style containing a single diamond and nothing
Step Cut -- A style of cut that is generally applied to square cut
gemstones. The step cut features rows of elongated facets that act
Symmetry -- Symmetry is the arrangement of the facets and
finished angles created by the diamond cutter. Excellent symmetry of
a well-cut and well-proportioned diamond can have a great effect on
the diamond's brilliance and fire. Grading reports will often state
the diamond's symmetry in terms Excellent, Very good, Good, Fair, or
Table -- The top surface of a cut diamond or gemstone.
Table facet -- This is the largest facet of a diamond. It
is located on the top of the diamond. The table facet is sometimes
referred to as the "face."
Table spread -- Term used to describe the width of the
table facet, often expressed as a percentage of the total width of
Tension Setting: A style of stone setting that uses tension to hold
gemstones between pieces of fine metal.
Trillion Cut: A type of gem gut where the gemstone is cut like a
Ultraviolet Light: These invisible light waves are used to examine a
diamond to detect characteristics and flaws. UV light can have a
positive or a negative effect on a diamond’s appearance depending on
the gemstone’s quality.
Well cut - Well-cut proportions ensure the maximum
compromise between fire and brilliance. When light enters a properly
cut diamond, it is reflected from facet to facet, and then back up
through the top, exhibiting maximum brilliance, fire and sparkle.