Tiny nicks along facet junctions, producing white fuzzy lines instead of sharp
crisp facet edges.
A step cut in the shape of a small rectangular stone which may be
tapered at one end.
Bearded girdle or Bearding:
Tiny, numerous, hair like fractures extending into the stone.
A facet on the Crown, or upper part of the Diamond above the Girdle.
Surface imperfection external to the Diamond.
Industrial grade diamonds
An effect caused by a shadowy area visible in some fancy shapes, caused by
light leaking out the bottom of the Diamond.
An inclusions consisting of surface crumbling, often accompanied by
tiny, root like feathers.
This facet may appear whitish, or burnt, as a result of the cutter
polishing the facet "against the grain".
The metric carat, which equals 0.200 gram, is the standard unit of
weight for diamonds and most other gems. If other factors are equal, the more a
stone weighs, the more valuable it will be.
An inclusion consisting of a large or deep opening in the stone.
A tiny piece missing caused by normal wear and tear, or by cutting.
A stone's relative position on a flawless to imperfect scale. Clarity
characteristics are classified as inclusions (internal) or blemishes
(external). The size, number, position, nature, and color or relief of
characteristics determines the clarity grade. Very few diamonds are flawless,
that is, show no inclusions or blemishes when examined by a skilled grader
under 10X magnification. If other factors are equal, flawless stones are most
A group of tiny white inclusions which result in a milky or cloudy
A diamond colored by a surface coating which masks the true
body-color; the coating may be extensive (entire pavilion, for example), but is
more often limited to one or two pavilion facets or a spot on the girdle.
Grading color in the normal range involves deciding how closely a
stone's body color approaches colorlessness. Most diamonds have at least a
trace of yellow or brown body color. With the exception of some natural fancy
colors, such as blue, pink, purple, or red, the colorless grade is the most
The upper part of the diamond above the girdle. It consists of a large flat
area on top called a table, and several facets below it.
The smallest facet at the bottom of the diamond.
The proportions and finish of a polished diamond (also called make).
Cut can also mean shape, as in emerald cut or marquise cut. Proportions are the
size and angle relationships between the facets and different parts of the
stone. Finish includes polish and details of facet shape and placement. Cut
affects both the weight yield from rough and the optical efficiency of the
polished stone; the more successful the cutter is in balancing these
considerations, the more valuable the stone will be.
A step cut, usually rectangular.
A facet placed without regard for symmetry and not required by the
Plane, polished surface of a diamond.
Sometimes cutters polish the girdle into 32 or more facets.
A diamond with an attractive natural body color other than light
yellow or light brown.
A separation or break due to either cleavage or fracture, often white
and feathery in appearance.
An imperfection of a stone.
A crack on the Diamond's surface.
The outer edge or the widest part of the diamond forming a band around
Grain Center :
A small area of concentrated crystal structure distortion usually
associated with pinpoints.
Mineral's resistance to scratching on a smooth surface. Mohs scale of
relative hardness consists of 10 minerals, each scratching all those below it
in scale and being scratched by all those above it.
Pure, spectral (prismatic) color. Hues include gradations and mixtures
of red, orange, yellow, green, blue, violet and purple.
Included Crystal :
A mineral crystal contained in a diamond.
Imperfection internal to the Diamond.
Internal indications of irregular crystal growth. May appear milky,
like faint lines or streaks, or may be colored or reflective.
A diamond which has been exposed to radiation.
An included diamond crystal which reaches the surface of a polished
Laser Drill Hole:
A tiny tube made by a laser. The surface opening may resemble a pit,
while the tube usually looks needle-like.
Magnifying glasses usually of 10X.
Small Diamonds less than .20 carat.
The ten-point scale of mineral hardness, keyed arbitrarily to the
minerals talc, gypsum, calcite, fluorite, apatite, orthoclase, quartz, topaz,
corundum, and diamond.
Part of the rough Diamond remaining on the Diamond, having survived
the cutting process. This is usually the sign of a good cutter attempting to
maximize the weight retention of the rough Diamond.
A long, thin included crystal which looks like a tiny rod.
A notch near the girdle or a facet edge.
A poorly proportioned Diamond.
Old European Cut:
Early round cut similar to the Round Brilliant Cut, but carrying a
very small table and heavy crown. Not as popular today because it does not
return the same brilliance as the modern brilliant.
The bottom part of the Diamond, below the girdle.
Miniscule spots internal to a Diamond. A cluster of pinpoints can form
A tiny opening, often looking like a white dot.
100th of a carat.
Tiny parallel lines left by polishing. Fine parallel ridges confined
to a single facet, caused by crystal structure irregularities, or tiny parallel
polished grooves produced by irregularities in the surface.
Surface clouding caused by excessive heat (also called burn mark, or
burned facet), or uneven polished surface resulting from structural
A grainy or pitted girdle surface, often with nicks.
Round Brilliant cut:
The most common cut containing 58 facets. Also the most brilliant cut,
in terms of most efficient use of light to increase brilliance and fire, hence
A color's position on a neutral to vivid scale.
A linear indentation normally seen as a fine white line, curved or
A Diamond with a large table and a thin crown height.
Refers to surface indication of structural irregularities. May resemble faint
facet junction lines, or cause a grooved or wavy surface, often cross facet
A color's position on a colorless-to-black scale.
A diamond with a body color induced by some form of artificial irradiation,
often in conjunction with controlled heating (known as annealing).
A cloudy area produced by crystal structure distortion, usually
associated with twinning planes.