DFJ Glossary
Learn about many of the terms used in fine jewelry.

Alloy

A mixture of various chemical elements. In jewelry, most often used when discussing gold.

Bezel

A setting style that refers to a ring of metal that encloses within it a gemstone. Offers a protective outer layer for the inwardly placed stone.

Bridge

Uppermost section of the ring that holds the crown; this part sits on top of the finger.

Carat

The measurement of weight for all gemstones. Fun fact, the word ‘carat’ derives from the carob seed that was used long ago as a way of measuring small amounts. 1.00 carat = 0.2 grams.

Ceramic

Term used to encompass materials such as porcelain, stoneware, and earthenware that is both resistant to heat and corrosion.

Clarity

A grade based on the presence or lack of inclusions and blemishes.

Cobalt

Elemental Symbol: Co
Derived from the German word ‘kobald’ meaning Goblin. Silvery-blue in appearance. It is also magnetic.

Crown

The part of the diamond above the girdle.

Cushion Cut

A combination of the round brilliant cut and the princess cut diamonds that showcases a roundish-square look.

Cut (Shape)

Determined by the overall look and facet pattern of a gemstone such as a round brilliant, emerald, oval, asscher, radiant, cushion, marquise, princess, pear, etc.

Asscher Cut

Also known as a square emerald cut, this stone is often described as resembling that of an endless hallway of mirrors.

Blemish

A flaw externally, on the surface of a gemstone.

CAD

Acronym for computer aided design, which uses computers to transform ideas into three dimensional digitized images. This, in turn, allows for enhanced visualization. Modifications can be made quickly and relatively inexpensively. Subsequently, lending to a more accurate end result and heightened actualization of the desired product.

Casting

(n.) The blank (without stones) metal replication of a jewelry design.
(v.) The action of pouring liquid metal into a mold

Certification

Term used to for a gemstone that has been sent to an independent laboratory for grading and/or identification. Can be considered today as the 5th "C".

Clasp

A mechanism that allows for easy removal and addition of jewelry on the body.

Color

The lack of or presence of another hue within a diamond. Most commonly yellow or brown. Diamond color may range from colorless (DEF), near colorless (GHIJ), faint (KLM), very light (NOPQR), to light (STUVWXYZ).

Culet

Bottom facet (or tip) of a gemstone. Old-mine cut and Euro cut diamonds will have larger culets whereas the modern cuts will have small or no culets.

Cut (Grade)

A grade assigned based on 12 factors that help determine how well a round diamond is finished. Cut grades are Excellent, Very Good, Good, Fair, or Poor. This directly affects the brilliance, fire, scintillation, and overall aesthetic appeal of the diamond.

Depth

Measurement of the height of the gemstone. Expressed as a percentage, it is calculated by dividing the height by the width (average girdle diameter) of the gemstone. Ideally, the depth of the stone will not be too shallow nor too steep. Different cuts call for different ranges of depth percentage.