"C" catch: The most common means of securing a brooch before 1900 or so when "safety catches" were invented. The pin connected to one side of the brooch is threaded through a layer of the garment and rests in a "C" shaped catch on the other side of the brooch. The "C" had no mechanism to hold the pin in place and so the pins were usually designed to be long enough to extend far enough beyond the end of the brooch to weave back into the garment for security.
Cabochon (pronounced cab-oh-shawn): A dome-shaped stone without facets
Casting: Method of shaping metal by melting and then pouring into hollow mold. The casted piece is slightly more porous, with a rough surface that requires additional polishing and finishing.
Channel Setting: Stone setting method that fits stones of uniform size into a channel to form a continuous strip.
Chaton Cut: Round crystal jewelry stone shape with 12 facets on the pointed back.
Choker: A short necklace, generally less than 14" long.
Crystal: There are two basic kinds of crystal - rock crystal and man-made. Rock crystal is the common name for the silicate mineral, quartz, which is a semi- precious stone that occurs in nature. Man-made crystal is produced from a mixture of quartz and, soda, potash, and lead oxide. Swarovski is a man-made crystal. Oddly enough, rock crystal has nowhere near the color or brilliance of manufactured crystal.
Calibré Cut: Small stones that are often step-cut and rectangular. They are made to set into a certain size and shape setting or are set against another stone.
Cameo: A layered stone (frequently banded agate) or sea shell that has been carved with either a woman's profile (most common), a man's profile, a natural scene or themes involving the Greek and Roman gods and goddesses. As the carver removed material from the surface the different layers beneath were revealed, most often showing different colors or shades which created a great, 3-dimensional quality to the scene or image.
Cameo Habillé (pronounced Cameo Hab-ee-yay): Most often, this is a depiction of a female who is carved wearing a diamond pendant, earrings or crown. The carver adds a small stone to the piece by drilling a small hole in the cameo, then setting the tiny stone which is wired to the back of the cameo.
Cannetille: A wirework decoration which uses coiled and twisted gold wire to achieve a delicate scrolling effect. It has a similar look to filigree.
Carnelian: Sometimes called cornelian. A translucent red or orange variety of chalcedony, sometimes banded red and orange like an agate. It is a grounding stone that boost personal prosperity and energy. Most carnelian comes from Brazil, India, Siberia, and Germany
Carat: A unit of mass used to measure diamonds, pearls and other gems. One carat equals 200 milligrams.. There are 100 points in a carat.that are 2 milligrams each.
Cartouche: An oblong design that holds an inscription. In Ancient Egypt they had a flat line at the bottom which meant a royal person or deitys name was written on it.
Casting: The technique of forming a substance, like glass or plastic or any substance that can be melted, into a specific shape with the use of a mold (see also "lost wax process")
Catalin: A brand name for bakelite. It is a thermoset polymer that can be cast and worked with files and saws eventually being polished.
Celluloid: A very thin, highly flammable plastic containing camphor. Celluloid is an early plastic that was invented in 1868 and used in jewelry to simulated tortoise shell, coral and alabaster. It was quickly abandoned for heavier, more stable plastics invented in the later part of the 19th century.
Celluloid brand: A trademark of Hyatt Brothers, Newark, NJ (1868), made of soluble guncotton and camphor, resembling ivory in texture and color. Celluloid can also be dyed to resemble coral, tortoise shell, amber, malachite and other natural stones. Should not be confused with the harder plastics such as Bakelite or Catalin. Because Celluloid is highly flammable, it enjoyed a brief popularity before it was replaced by more stable products which came into existence in the `1930’s, the phenolic resins.
Celtic: Designs that are derived from the ancient Irish, Gaelic, British, Scottish & Welsh symbols
Chasing: A method of decorating the front, (or outside), of metal objects by making indentations using shaped punches and a chasing hammer. The opposite of chasing is repoussé.
Chaton: A faceted stone that is round.
Champlevé: An enameling technique in which areas of metal are cut, etched or routed and then filled with enamel (molten glass). Most commonly applied to copper or bronze.
Channel Setting: A setting, usually narrow (hence "channel"), into which stones of the same size and cut have been tightly set, without prongs; the tension between the stones held in the channel is what holds them in, thus omitting the need for prongs. Created by Cartier in the 1920's.
Chatelaine (pronounced "Chat-ah-lain"): In Victorian days, woman did not have pockets. A chatelaine was pinned at a woman's waist, with several chains suspended from it, most commonly holding scissors, keys, thimble, comb and other household necessities. Today, a chatelaine pin most commonly refers to 2 pins that are joined together by small chain(s).
Choker: A close fitting necklace worn tight around the neck like a collar.
Chrome: A hard, brittle, grayish-white metal, fusible with difficulty and resistant to corrosion. Its chief commercial importance is for its compounds, as potassium chromate, lead chromate, etc., which are brilliantly colored and are used dyeing and calico printing. The common modern usage is for very shiny metal objects like chrome bumpers on cars.
Cire-perdue: The French word for lost-wax casting. see "Casting"
Clip: A dress clip is like a brooch, except instead of having a pin stem on the back it has a folding clip that enables it to be worn or used in a variety of ways. A fur clip also has a folding mechanism on the back, but the mechanism is made of 2 sharp prongs and was originally used to hold fur wraps around a woman's neck. They were popular in the 1920's through the 1940's. Today they are very collectible, and can be used in many ways.
Cloisonné (pronounced "cloi-zon-ay"): Another technique of enameling whereby the enamel (colored glass powder) is placed into pockets or cells of metal, then baked and cooled to solidify. The metal portions have high "walls" to keep the colors from running into each other during firing.
Copper: A common, reddish-brown metallic element, Copper is the only metal which occurs abundantly in large masses as opposed to small veins or nuggets that must be mined out of other rocks. It is also found in various ores such as chalcopyrite, chalcocite, cuprite, and malachite. When alloyed with tin it forms bronze, and when alloyed with zinc it forms brass. Copper is an excellent conductor of heat and electricity and is widely used for electrical wiring as well as water piping and corrosion-resistant parts. When in moist conditions, a greenish layer forms on the outside. It has been extracted and used for thousands of years.
Coral: Coral is a form of calcium carbonate, (like aragonite or marble), secreted in long chains by coral polyps who live in colonies under the ocean. Coral can be found all over the world, but the bulk of coral used in jewelry making has always come from the waters off Sardinia and the coast of Sicily in the Mediterranean. Coral comes in colors from vivid orange, red, and white, to salmon and pale pink (called angelskin coral). In jewelry making coral is either carved into beads,cameos, and other forms, or is left in its natural branch-like form and just polished. During the mid-Victorian era large cameo brooches of coral finely carved in high-relief floral sprays or faces were popular. It used to be thought that coral protected the wearer, so it was a traditional gift to children. Since it is composed of calcium carbonate, real coral will effervesce if touched with acid (like lemon juice). Imitation coral is made from glass, porcelain, or plastic and will not effervesce when touched with acid.
Cubic Zirconia: Cubic Zirconia are man made gems which appear very much like diamond yet do not have the same intrinsic properties such as hardness. “CZ’s” as they are often called, are mass produced and much less expensive than natural diamonds but it is nearly impossible to tell the diference between the two stones with the naked eye.
Culet: The flat face on the bottom of a faceted gemstone.
Cultured pearl: When an oyster or mollusk is artificially "seeded" with a tiny grain of sand. The mollusk then excretes a coating to protect itself from the irritant. Several layers are accreted creating a real, freshwater pearl. See freshwater pearl
Cushion Cut: A square or rectangular stone that has rounded corners, also called "antique cut". The older form of the brilliant cut having a girdle outline approaching a square with rounded corners. Essentially an "old-mine cut". (See also "Mine Cut")
Cut Steel: Steel studs that have been machine stamped, cut with facets and highly polished. In the days before electricity the faceted steel would be quite brilliant, giving the impression of gemstones in candlelight. Most frequently used from 1750-1870; highly susceptible to rust and corrosion. Finding it in good condition today is not common.