Glossary

Precious or semi-precious stone that is merely polished without being cut into facets and was much used in the Middle Ages.

Cameo

Relief carving (a carving that comes up above the surface) on a shell or stone. In multi-colored cameos, a layered substrate is used (with two different colors), and when part of the upper layer is carved away, the second color emerges as the background.

Carat (or Karat)

The unit of measure for gold and gemstones (abbreviation: ct. or kt.). One carat weighs 0.2 gram (1/5 of a gram or 0.0007 ounce). A hundredth of a carat is called a point . The carat unit was introduced in 1907 (24 kt. is 100% gold; 18 kt. 75% gold; 14 kt. 58.3% gold; and 10 kt. 41.7% gold).

Champlevé

Enamelling technique in which a design is scooped out of a copper ground and then filled with opaque enamel and fired, fusing the enamel so that it is flush with the reserved metal.

Chasing

Chasing is a type of metal decoration in which the metal is manipulated using a hammer and a punch, resulting in an effect similar to engraving or embossing .

Claw

A claw is a metal prong that holds a stone securely in a setting.

Claw setting

Projecting metal prongs (called claws) are bent over the stone to hold it securely in place.

Cloisonné

Method of applying enamel to metal in which the design is first outlined on the metal surface using a metal wire; the space between the wires is filled with enamel and then fired to a glassy sheen.

Collet

Thin, round band of metal that goes all around the stone.

Collet setting

Early method of setting gemstones, in which one edge of the metal collet is crimped over the edges of the stone and the other edge is soldered to the metal of the jewelry, holding the stone in place.

Dextrarum junctio

Motif known since antiquity of two hands clasped in faith, also called “fede” and symbolizing the union of marriage.

Electrum

Naturally occurring amber-colored alloy of gold and silver that was used in ancient times; in the medieval era electrum is also an alloy consisting of copper (50%), nickel (30%) and zinc (20%).

Enamel

Siliceous substance fusible upon metal, either transparent or opaque and with or without color, but it is usually employed to add decorative color to metal. Enamel can be applied in many different ways, including cloisonné , champlevé , and plique à jour.

Engraving

Technique of cutting patterns into a surface with a sharp tool; an impression made from the cut surface shows the design of the incised lines in reverse (hence intaglio).

Fede

From the Italian for “faith” or “trust” fede rings are symbolic rings shaped in the form of two clasped hands. Such rings were popular in ancient Rome as betrothal rings and again throughout Europe from the twelfth to the eighteenth centuries.

Filigree

Ornamental work composed of fine grains or beads, or sometimes of wires soldered to a background but often left as openwork.

Foil

Thin metal backing for gems to increase their brilliance, used from Antiquity through the Renaissance with precious stones as well as glass.

Forged

Metal formed by heating it in a forge (furnace) and beating or hammering it into shape.

Gemstone

Gemstone (also called a precious stone) is a mineral that is valuable, rare and often beautiful.

Granulation

Decoration consisting of minute spherical grains of metal soldered to a background usually in gold; the ancient method which left no solder visible between the grains and the surface of the gold was rediscovered only in the twentieth century.

Hallmark

Mark stamped on jewelry throughout much of the world to attest to the purity of the metal after assay . European hallmarks are legally required and date back to the early Middle Ages.

Hoop

Also called the shank, the rounded part of the ring that encircles the finger and connects to the bezel at the shoulders.

Intaglio

Intaglio is a method of decoration in which a design is cut into the surface, the opposite of cameo. Signet rings are frequently decorated with intaglio, as are seals.

Leaf

Metallic leaf is paper-thin sheets of metals. For example, gold, silver, platinum, and copper are rolled or pounded into metallic leaf which can be applied to surfaces.

Memento Mori

(Latin: "Think of Death"). A term to describe objects incorporating emblems of mortality, skulls, cadavers, coffins, etc., designed to remind the viewer of the inevitability of death.

Niello

Ancient technique in which an engraved design in metal is filled with powdered niello alloy in a dark grey or black color (composed of silver, copper, lead, and sulphur). The niello alloy is melted (the entire metal piece is heated in a kiln) and fuses with the underlying metal. The object is then polished and the result gives the effect of enamel. Niello has been made at least since the time of ancient Rome.

Paillons

Small pieces of metallic foil, sometimes in colors, which are placed underneath a translucent stone to enhance its color and make it more luminous.

Paste

Term used for imitation gemstones made of glass or other vitreous substances.

Posy

From “poesie” for poetry, a posy ring is one with an inscription usually on the interior of the band and was especially popular in Elizabethan and Tudor England.

Rosecut

Cut for diamonds invented in the seventeenth century and continued until the eighteenth century. The rose cut has a flat base and triangular facets (usually 24). This cut has little wastage of stone, but is not nearly as reflective as the brilliant cut , which was invented later.

Seal

Mounted in rings or hung on a chain, seals were once extensively used as a means of identification and only by relatively important people. Seals are carved in hard stones (like sard or jasper ) using intaglio or engraved on gold signet rings.

Setting

Setting is a method of securing a stone (or other ornament) in a piece of jewelry (or other object). There are many different types of settings, including the collet, claw, cut-down, and pave, among others. Some settings are closed (there is metal behind the stone), while others are open (there is no metal behind the stone), letting light shine through the stone.

Shell cameo

Cameo made from a shell.

Shoulders

Often articulated, the shoulders are the part of the ring between the hoop (or shank) and the bezel.

Signet ring

Ring used for signing, thus often with the coat-of-arms or the initials of the wearer's family incised in reverse on the bezel. The earliest-known signet rings date from ancient Egypt, thousands of years ago.

Soldering

Process by which different metallic parts are joined to one another with any fusible alloy, usually tin and lead.

Step-cut

Also known as a trap cut, the step cut has one large facet surrounded by rectangular facets. Smaller step-cut stones are often used as accents and are called baguettes.

Table-cut

One of the earliest styles of gem cutting, based on the natural octahedron, one of the forms in which diamond crystals occur. The top of the octahedron is cut off to leave a flat surface with the pointed half of the octahedron below.