DIAMOND EDUCATION

Diamond and Jewelry Terminology

This quick reference guide contains common diamond and jewelry terminology and their meanings. Use the letter links below to quickly find a diamond or jewelry term.

A B C D E F G H I J K L M O P R S T U W Y

Adamas: Greek word for indestructible; origin of the word diamond

Antwerp: center for the distribution of rough and polished diamonds; more than half of the world's production of rough, polished, and industrial diamond passes through this city

Appraisal: official valuation document made by a certified gemologist and expert in field of diamonds and metals

Asscher: diamond shape named after the world-renowned cutter Joseph Asscher; square with cut corners

Baguette: rectangular-shaped step cut most commonly used to complement larger diamonds

Bezel: setting in which metal rim secures diamond at the girdle; permits diamond's light-throwing abilities while protecting the stone

Black Diamond: diamond saturated with graphite inclusions

Blemishes: external characteristics (flaws) or surface irregularities

Bourse: diamond-trading markets where members buy and sell goods

Bow-tie Effect: area of less brilliance that appears like a bowtie; occurs in certain fancy-shape diamonds when the stone's proportions are poor

Brilliant-cut: triangular-shaped facets, typically numbering 57, pointed toward the outer part of the diamond

Canary: fancy color diamonds with an intense or vivid yellow color

Carat (ct.): unit of metric measurement used for diamonds; one carat equals .2 grams, or .007 ounces

Certification: a document issued by an independent gemological laboratory that details the vital characteristics of a diamond along with carat, color, clarity, and cut

Channel: setting with uniform diamonds mounted in a grooved channel; diamonds are secured as a group and are not separated by metal as in other setting styles

Clarity: internal and external characteristics of a diamond visible under 10x magnification

Clasp: closure used in bracelets and necklaces for security

Color: rating of the degree of color of a diamond as compared to a master stone(s)

Crown: portion of faceted diamond above the girdle

Crown Angle: relationship of the crown to the girdle; measured in degrees

Culet: small facet polished at the bottom of the pavilion

Cushion: square shape with rounded corners

Cut: refers to diamond shape and/or quality of cut

Cut Grade: GIA rating of polish, symmetry, weight ratio, brightness, scintillation, and fire

Depth: measurement of diamond from the top of the crown to the bottom of the pavilion

Depth Percentage: width ÷ depth = depth°

Diamond: mineral composed entirely of the element carbon

Dispersion: light that shoots through the top of the diamond displaying a color spectrum

Emerald: diamond cut shaped after the way emerald gemstones are cut; shorter in length than a proper rectangle

Facet: flat, polished surface on a diamond

Fancy Color: color in a diamond that increases the stone's value

Fancy Shapes: any shape other than round-cut

Finish: quality of a diamond's polish and symmetry

Fire: light that enters a diamond and is then returned to the viewer

Fluorescence: light emitted from a diamond when the stone is exposed to UV light; often a blue hue

Girdle: band across widest part of a diamond; divides the crown and pavilion

Gold: chemical element Au; most common metal for jewelry because of its beauty and durability

Gold Purity: expressed in karats ('K'). Gold is alloyed with other metals such as silver, copper, zinc, or silicon to produce purities less than 24 carat. Finest gold used in jewelry is 18K (75% pure) or 14K (58.5% pure)

Grain: 1/4 of a carat; 1ct = 4 grains

Grams: unit of weight measurement; used for gold weight

Heart: a pear-cut with two rounded edges instead of one

Hearts and Arrows: ideal-cut symmetrical diamonds will exude arrows when viewed "face up" and hearts when viewed "face down;" can be seen with certainty only under a special microscope

Ideal-cut: polished diamond with exceptional make and light performance

Inclusion: internal characteristic in a diamond

Intensity: concentration of color in fancy color diamond; value is closely tied to a colored diamond's intensity grade

Johannesburg: diamond center in South Africa

Kimberlite: volcanic rock formation in which 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: magnifying glass used in the diamond industry

Make: refers to the craftsmanship of a diamond's cut and finish

Marcel Tolkowsky: published modern diamond cutting method in 1919; known as the originator of the modern brilliant round-cut diamond

Marquise: twice as long as it is wide with pointed ends; named after Marquise de Pompadour's smile

Master Stone: diamond of a predetermined color that is used for comparison in diamond markets and laboratories around the world

Measurements: width1 x width2 x depth (expressed in millimeters)

Mix-cut: diamond cutting method using brilliant-cut and step-cut faceting techniques

Oval: elongated round-cut diamond

Pave': multiple small diamonds set as closely together as possible in two or more rows

Pavilion: portion of faceted diamond below the girdle

Pavilion Angle: relationship of the pavilion to the girdle; measured in degrees

Pear: diamond-cut comprised of the brilliant round-cut and marquise-cuts; resembling tear drop

Platinum: chemical element Pt; silver-white in color and used in its pure form for jewelry

Polish: quality and smoothness of polished diamond surface

Pressure: setting type that uses pressure to hold multiple diamonds in a mounting

Princess: square cut diamond with 90-degree-angled corners

Prong: setting type in which diamonds are held in place by fine metal prongs

Radiant: square to rectangular diamond shape with cut corners

Reflection: immediate reflection of light given off by a diamond's surface

Refraction: light that bounces off the internal wall(s) of the diamond

Report: gemological certificate

Rhodium: process in which gold is dipped in a protective alloy to prevent tarnishing and make the metal white

Rough: any uncut diamond

Round: round-shaped brilliant-cut diamond

Scintillation: reflections from the facets of a diamond seen as the stone is turned in the light

Solitaire: a ring containing a single diamond

Star Facets: triangular facets along the table

Step-cut: rows of elongated facets that act like mirrors

Symmetry: shape and precision of facet arrangement in a diamond

Table: top flat facet of a polished diamond

Table Percentage: comparison of the size of the table facet to the width of the diamond at the girdle in percentage

Tension: setting that uses tension to hold a diamond between fine metal

Trilliant, Triangular: diamond shaped like a triangle

Ultraviolet Light: invisible light waves that can have a positive or negative effect on a diamond's appearance

White Gold: gold mixed with white metals such as silver, palladium, or nickel

Yellow Gold: natural color of pure gold usually mixed with other metals (to dilute purity)