Baddeleyite
A mineral with the same chemical composition as cubic zirconia. It is powdered, melted down, and mixed with oxides to make cubic zirconia.

Baffa diamond
Baffa diamond is actually rock crystal and not a real diamond.

Baguette
A gemstone cut in a narrow rectangular shape reminiscent of a loaf of French bread, from which it draws its name. Small diamonds cut this way are often used as accents for rings and necklaces.

Bail
A hoop-like attachment for a pendant that allows a pendant to be worn on a chain or
necklace. Some pins or brooches are supplied with removable bails. These are usually made by soldering a hoop to a small tube which can then be slipped over the pin stem so the piece can also be worn as a necklace on a chain, collar or omega necklace.

Bakelite
A moldable plastic invented by Leo Bakeland in 1909, it was used in jewelry extensively during the U.S. Great Depression of the 1930's. Bakelite can be molded, lathe-carved, and one color can be inlaid into another, as in polka dots. The inlaid and carved pieces are especially popular with collectors today. It has a distinct scent when rubbed similar to formaldehyde.

Bale
See Bail.

Band
A ring, (such as a traditional wedding band), that has the same width all the way around.

Banded agate
Banded agate is a type of agate with distinct layers of color.

Bangle
A bangle is a stiff bracelet. Some bangles have a hinge (like the Miriam Haskell bangle pictured above); others are solid and must be slipped over the hand.

Bar and Ring Clasp
A bar and ring clasp (also called a toggle clasp) is a jewelry fastener in which a bar can be inserted into a ring to fasten a pice of jewelry. It is used to attach the two ends of a necklace or bracelet.

Bar Brooch
A bar shaped, (long, narrow), brooch which is often set with gemstones or pearls.

Barclay
Barclay was a Providence, Rhode Island costume jewelry company that sold many of its pieces through Marshall Field Department store. It began production in May, 1948. One hallmark is an artist's palette, reading, "Barclay Art in Jewelry." Barclay is NOT the same as McClelland Barclay

Bar closure
A hinged bar which fits into a catch and is secured in the catch with a pin.

Baroda Gem
'Baroda Gem' is a trade name for a colorless glass stone with a foil back.

Baroque
A pearl with an uneven or craggy shape and/or surface. Also an irregularly shaped stone or glass bead.

Baroque pearls
Baroque pearls are irregularly-shaped pearls. Baroque pearls can be natural or artificial.

Bar Pin
A bar pin (also called a bar brooch) is a long pin that is worn horizontally

Barrel clasp
A method of securing two ends of a chain together by having one half of a fitting screw into the other half. When the two halves are screwed together they resemble a barrel.

Barrette
A barrette is an ornament worn clipped into the hair.

Basalt
A dark volcanic rock, often with a glassy appearance, composed chiefly of plagioclase, pyroxene, and olivine.

Base Metal
The collective term for any and all non-precious metals.

Basket
A fancy setting with a lacy or basket-looking appearance due to numerous holes pierced in the side.

Basse-taille
Basse-taille (meaning "low cutting" in French) is an enameling technique in which the underlying metal (usually gold or silver) is carved in low relief (the metal's surface is cut away by engraving or chasing, producing a sculpted surface). The highest point of the relief carving is below the surface of the surrounding metal. Translucent enamels are applied over the carved metal, allowing the design to remain visible through the enamel. The hue of the enamel changes with the depth of the glaze, resulting in subtle variations in color over the high and low design elements.

Baton
A baton is a stone that is cut in a long, thin rectangular shape. A baton is larger than a baguette.

Bauxite
A clay-like mineral, bauxite is the principal ore of aluminum. It is composed of aluminum oxides and aluminum hydroxides. Bauxite is used as an abrasive, a catalyst, and a refractory for the lining of furnaces which are exposed to intense heat.

bayadère
A bayadère is a pearl necklace that has many strands of pearls twisted together.

B. David
B. David is a mark used by the B. David jewelry company. This Cincinnati, Ohio, company was started in 1945 and is still in business. The company produces medium-quality costume jewelry pieces (often studded with rhinestones and faux pearls) and also now makes pieces from gold and silver. Marks from this company include B. David, b. David and bd (on the diagonal).

Beach Glass
Beach glass (also called sea glass) is glass from old broken bottles, windows of wrecked ships, etc. that has been worn down and etched by the sea and sand over the years. This glass is smooth and looks like beautifully sand-blasted glass and has a beautiful patina. Pieces of this glass are collected on beaches and often made into jewelry items. Brown, deep green and clear are the most common colors of sea glass; after these come blue, amber and aqua. Rare colors include pink, red, purple, light yellow, and sea green.

Bead
A small, usually round, object with a hole pierced through it to be strung as a necklace, bracelet, etc. Beads are commonly made from stone, shell, glass, or plastic.

Beau and Beaucraft
Beau and Beaucraft are marks used by the costume jewelry company called Beaucraft, Inc. This Providence, Rhode Island company was started in 1947 and is still in business. Beau and Beaucraft pieces come in a variety of styles (including many figurals) and compositions; pieces are made from silver, goldplated metal, gold over silver, and 14kt gold.

Bell Cap
A bell cap is a jewelry finding that is used to convert a hole-less bead or stone with into a pendant. A bell cap is glued onto the bead or stone and had a loop for attaching to the piece of jewelry.

Belle Epoque
The Belle Epoque (meaning "Beautiful Time" in French) was the Edwardian period, the time of the reign of Edward VII of England (1901-1910).

Belly Ring
A form of body jewelry worn in or on the belly button.

Benitoite
Benitoite is a rare, blue gemstone that is found mostly in the San Benito River in San Benito County, near Coalinga, California (lesser quality benitoite is found in Mont St. Hilaire, Quebec, Canada). Benito means "blessed" in Spanish. This gemstones is strongy dichroic; although Benitoite is blue when viewed from most directions, it appears colorless when viewed in a single direction (the c-axis). Some unusual Benitoite is blue, but pink or orange when viewed through the c-axis. Benitoite is BaTiSi3O9 (Barium Titanium Silicate); no one is sure what element causes the blue color of benitoite, but it may be iron. Benitoite has a hardness of 6 - 6.5, a specific gravity of 3.68, and a refractive index of 1.757 - 1.804. Benitoite has a very unusual crystalline shape - it is the only known ditrigonal-dipyramidal crystal. Large stones (over 1 or 2 carats) are exceedingly rare. Benitoite was discovered in California in 1907, either by Mr. Hawkins and T. Edwin Sanders or James Marshall Couch (the story is in dispute). Heat-treated benitoite becomes orange; these stones are more expensive. Benitoite is California's official state gemstone (since 1985).

Bergere
Bergere is a mark used on costume jewelry made by the company Herbet and Pohs, Inc. This medium- to high-quality costume jewelry has been sold in stores like Lord and Taylor and Marshall Fields.

Beryl
Beryls are a family of gemstone that include emerald, aquamarine, beryl (green), red (red beryl), morganite (pink), and heliodor (greenish yellow, named for the sun), and goshenite (colorless). Beryl has a hardness of 7 - 8, a specific gravity of 2.6 - 2.9, and the chemical formula Be3Al2SiO6. Internal flaws in beryl gems can be hidden by treating the stone with oil (this is often not disclosed to the buyer).

Beryllium
Another name for Glucinum.

Betrothal Ring
A tradition dating back to as early as ancient Rome where it was called an anulus pronubus, a betrothal ring is usually a plain ring without a stone presented by a man to his fiancée indicating their intention to marry.

Beveled
Any surface that is cut at an angle less than 90 degrees.

Bezel
Although it is now often used to refer to the entire ring setting, the bezel is more accurately the term for the metal case which the gem is set into. The ring of metal that surrounds the stone is called the "collet".

Bezel Set
A bezel setting is a technique of setting a stone in jewelry. The stone is held in place by first soldering the bezel, or metal ring, to the base of the piece. Next, the stone is inserted and the metal is compressed tightly around the stone.

Bib Necklace
A bib necklace (also known as a collarette) is a short necklace with flowing ornaments in the front.

Birefringence
Birefringence is another name for double refraction. In doubly-refractive stones, the light entering the stone is split into two light rays, and the rays travel in different paths. These stones have more than one refractive index. Calcite, peridot, zircon, tourmaline, and titanite are doubly-refractive stones.

Birthstone
Birthstones have their roots in ancient astrology, and there have been many birthstone lists used over the years. The most common one today is based on a list first publicized by the Jewelers of America in the 1950s:
January - Garnet
February - Amethyst
March - Aquamarine
April - Diamond
May - Emerald
June - Pearl or Moonstone
July - Ruby
August - Peridot
September - Sapphire
October - Opal
November - Citrine
December - Turquoise (or Blue Topaz)

Biwa pearls
Biwa pearls are freshwater pearls from Lake Biwa in Japan. These irregularly-shaped pearls are smoother and more lustrous than most other freshwater pearls.

Black Hills Gold
A style of jewelry made in the Black Hills area of South Dakota featuring 10kt yellow gold with accents of 12kt rose and green golds usually featuring a grape and grape-leaf motif.

Black opals
Black opals are a valuable type of precious opals with a dark ground color. They are luminous, iridescent, and frequently have inclusions of many colors ("fire"). Opal is a mineral composed of silica (and some water) and is a species of quartz. The rainbow-like iridescence is caused by tiny crystals of cristobalite. Many opals have a high water content - they can dry out and crack if they are not cared for well (opals should be stored in damp cotton wool). Opals have a hardness of 5.5 to 6.5 and a specific gravity of 1.98-2.50. Black opals are found in Australia.

Black Onyx
Opaque black colored onyx.

Black pearls
Black pearls (also called Tahitian pearls) are dark-colored pearls. They are produced by the large, black-lipped pearl oyster Pinctada margaritifera (also called the Tahitian black pearl oyster), a mollusk found in the tropical Indo-Pacific Ocean. Black pearls come in many colors, including many body shades and overtone tints including gray (light gray to almost black), peacock green (especially valuable), aubergine (eggplant), and deep brown. The color of the dark nacre is determined by the minerals in the oyster's diet (plankton) and in its environment. Many "black pearls" are dyed or irridiated to enhance or change their color; it is difficult to tell a natural pearl from a treated pearl. Tahitian pearls are graded on six factors: 1.Shape (round is most valued), 2.Size (the larger the better), 3.Surface Quality= (clean is superior to blemished), 4.Luster (the more high-gloss luster the better), 5.Nacre Thickness (thicker is better and longer lasting), and 6.Color (overtones atop the body color add value to the pearl. The most sought-after color is peacock green and darker colors are more valuable Overtone colors include blue, pink, gold, silver, aubergine, and peacock green).

Black Prince’s Ruby
Not an actual ruby, but a ruby-red color of spinel.

Black Star Diopside (Black Star Of India)
Black star of India is another name for Black Star diopside (CaMgSi2O6), an opaque black gem with a white, four-rayed star (an asterism). It has a hardness of 5.5 and a specific gravity of 3.3 - 3.6. These stones are found mostly in India. Stones are generally cut cabochon and are not enhanced.

Bleaching
Bleaching is a process in which a gemstone's color is removed using a bleaching agent.

Blemish
A flaw, such as a nick or scratch, on the surface of a stone.

Bling bling
Bling bling is an American slang term used to describe large, showy jewelry, especially jewelry encrusted with diamonds. The term was coined in the late 1990s by the New Orleans rappers Cash Money Millionaires.

Blister Pearl
A pearl that forms attached to the shell.

Bloodstone
Bloodstone is a soft green jasper mottled with red spots from iron oxide. A type of chalcedony it is also known as Heliotrope. Bloodstone is a relatively soft stone and is one of the ancient birthstones for February or March

Bloomed Gold
The term used for gold jewelry that has been immersed in an acid bath giving it a textured, slightly matte appearance.

Blue diamonds
Blue diamonds are rare, fancy diamonds and are quite valuable. Diamonds are precious, lustrous gemstones made of highly-compressed carbon; they are one of the hardest materials known. Diamonds have a hardness of 10, a specific gravity of 3.5, and a refractive index of 2.417 - 2.419.

Blue gold
Blue gold is gold with a bluish tinge. It has been alloyed with a mix that includes iron.

Blue Lace Agate
A translucent light blue agate with milky white banding.

Blue Topaz
A topaz that is light brown or colorless when mined but turns a vivid blue when exposed to heat. Blue Topaz is an alternate birthstone for December.

Bodkin
A bodkin is a heavily jeweled, Renaissance era hairpin.

Body Jewelry
Jewelry designed to be worn on or in any part of the body. While all jewelry is technically worn on the body, the term "Body Jewelry" is typically used when referring to belly rings, nose studs, toe rings, tongue bars, and for jewelry designed for pierced lips, eyebrows, nipples, or any skin surface.

Bog-oak
Bog-oak is old oak wood that has been blackened and preserved by being in low-oxygen Irish and Scotish peat-bogs for thousands of years. Bog-oak was carved and used as inexpensive Victorian era jewelry. It was also used for decorative objects, bowls, chests, dagger handles, and other decorative items.

Bogoff
"Bogoff" and "Jewels by Bogoff" are marks used on costume jewelry made by the Spear Novelty Company of Chicago, Illinois, USA. The Bogoff mark was first used in 1946. Bogoff jewelry is high-quality, was made in small runs, and is often studded with rhinestones.

Bohemain Diamond
A "Bohemian diamond" is not a diamond at all, it is actually a rock crystal.

Bohemian Garnet
Term for the red pyrope garnet found in much Victorian and turn of the century jewelry.

Bohemain Ruby
A Bohemian ruby is actually a pyrope garnet (and not a ruby at all).

Boke
Boke is a Japanese term for coral that is rose colored.

Bolo
A braided leather loop worn about the neck and adorned with a slide, (an ornament of silver, stone or other material fastened so that it slides up under the chin), leaving the two leather ends hanging.

Bolt Ring
A bolt ring (also known as a spring ring) is a hollow circular metal fastening ring with a spring opening. It is used to attach two other rings or links of a necklace or bracelet. The bolt ring was invented early in the 1900's. Jewelry made prior to 1900 or so will not

Bombé
The word itself simply means "curving or bulging outward". In regards to jewelry it refers to a dome-shaped setting often seen in rings and earrings from the 1940s and 1950s.

Bonding
Bonding is a process in which a colorless bonding agent (like plastic) is applied on and into a porous gemstone to make the stone more durable and give it an enhanced appearance.

Bone
Bone is animal bone, carved to make beads, pins, bangles, etc. It superficially resembles ivory, but has a less-complex characteristic internal patterns and a yellower color.

Book Chain
A Victorian style of chain made in gold, gold filled , and sterling silver, in which each link is a rectangular, folded piece of metal resembling a book. They were often elaborately engraved and had large lockets attached.

Boron
A soft, brown, nonmetallic element. It is extracted with some difficulty and in its reduced state appears as a substance of a deep olive color, in a semi-metallic form, and in colorless quadratic crystals similar to the diamond in hardness and other properties. Boron is used in flares, propellant mixtures, nuclear reactor control elements, abrasives, and hard metallic alloys.

Bort
Bort is a term for industrial grade diamonds.

Botanical Gems
Botanical gems are minerals that form from plants or plant material. Some botanical gems include amber (fossilized tree resin), coconut pearl (a rare, shiny, calcareous, pearl-like mineral that forms inside the coconut, Cocos nucifera), and pearl opal (also called Tabasheer opal, which form in injured bamboo joints).

Boucher
Marcel Boucher (?-1965) was a French jewelry designer who started the Boucher company ( in NY, NY). Boucher began the company: Marcel Boucher and Cie, which produced high-quality costume from 1937 to 1972 (after Boucher's death in 1965, his wife Sandra Boucher, who was also a jewelry designer, led the company - in 1972, the company was purchased by Dovorn Industries). Boucher had designed jewelry for the MAzer costume company before starting his own company. The bird pin above is gold-plated with paste and enamel. Boucher marks include "Marcel Boucher", "Boucher" and "Marboux."

Boulder Opal
Boulder opal forms on a dark ironstone base (the host rock) and occurs as a thin uneven layer adhering to the ironstone. Because of the uneven layers, sometimes part of the ironstone is visible on the surface of the stone.
Boulder opal is found in a wide range of colors including: green, blue, aqua, and pink. See opal varieties and opal description for more in depth discussions about this wonderful gemstone.

Bouton Pearl
A bouton pearl (also called a blister pearl) is a pearl that developed attached to the inside of the mollusk's shell. This type of pearl must be cut off the shell, and is therefore hemispherical (half a sphere). Because of their shape, blister pearls are mostly used for earrings.

Bow
Bows are a common motiff in jewelry. The pin pictured above is a sterling bow made by Trifari.

Bow-Guard
Originally just a wide leather strap worn on the left wrist to protect the arm from bow strings, it is now usually decorated with a wide ornament of silver.

Box Clasp
A method of connecting two ends of a chain. One end has a box with an opening which is notched on the top of the box. The other end has a flat piece of metal which has been folded over to form a spring with a knob at the end. The folded metal spring slips into the hole in the box with the knob sticking out through the notch in the top. The compressed spring holds the two ends in place. It is released by pressing the knob. The connection is usually reinforced by a figure 8 catch.

Box-and-tongue clasp
See Box Clasp.

Box Chain
A chain in which each link is wide and square so that it resembles a box.

Bracelet
A form of jewelry worn around the wrist.

Braganza
The Braganza is a huge gemstone that may or may not be a diamond. This Portuguese stone is said to weigh 1680 carats (which would make it the largest-known diamond), but it has not been authenticated - it may actually be a clear topaz.

Brass
An alloy made up of roughly half copper and half zinc which has a nice yellow color.

Brazilian chain
A Brazilian chain (also called a snake chain) is a metal chain made up of a series of small, linked cups.

Brilliant cut
Brilliant cut stones have 56 facets, 32 facets are above the girdle, 24 are below. Most modern-day diamonds are brilliant cut since it maximizes the amount of reflected light from the stone (its natural fire). The brilliant cut was introduced in the 1600's, possibly by Cardinal Mazarin (1602-1661), a politician and lover of gems.

Brecciated
Rock composed of sharp-angled fragments embedded in a fine-grained matrix. Some Jaspers and agates are brecciated (pronounced: bretch-e-ated).

Bridal set
An engagement and wedding ring that come in a set and usually match or compliment each other.

Bridge jewelry
Bridge jewelry is jewelry that "bridges the gap" between fine (precious) jewelry and costume jewelry. An example of bridge jewelry is sterling silver pieces.

Brilliance
The amount of sparkle a stone gives off through reflection and refraction of light.

Brilliant-cut
A cut gemstone having 56 to 58 facets to maximize the volume of light that is reflected from the inside and thus produce the greatest brilliance. The most common shape of brilliant cut stones are round, which is why this is type of cut is sometimes called a "round-cut", but oval, marquise, pear shape and heart shapes are not unusual.

Briolette
A gemstone cut with triangular facets into the shape of a teardrop or elongated pendant.

Britannia Or Pewter
An alloy of tin, antimony, and copper with a dull silver-color.

Britannia Silver
A silver alloy composed of 958 parts silver in 1000 hallmarked with the figure of Britannia. Britannia silver was mandatory in England from 1697 to 1720 to prevent the melting down of sterling coins to create silver objects.

Broker
See Agent.

Bronze
A very dense and heavy alloy of 60% copper and 40% tin. It has a dull brown color and is not favored for jewelry because of the weight.

Brooch
An ornamental piece of jewelry with a pin and clasp to be attached to clothing, from the French word "broche", meaning "to pierce" or an object/weapon made for piercing.

Bruiting
The term for shaping the girdle of a diamond, the first step in the cutting process.

Brushed Finish
A series of tiny parallel lines scratched onto a surface with a wire brush or polishing tool to produce texture

Bruting
Bruting is the first step in cutting a diamond. Bruting involves shaping the girdle, which gives the stone its basic shape.

BSK
BSK is a costume jewelry company that made mid-range pieces. This New York company was in business from around 1950 until the 1970's (?). BSK stands for the initals of the owners: B for Benny Steinberg, S for Hy Slovitt, and K for Kaslo. The BSK pin above is gold plated and decorated with rhinestones and enamel.

Bubbles
Bubbles are spherical or tear-shaped bubbles of gas captured in glass stones. Bubbles can also be found in resins (like plastics and amber), and much less-frequently in minerals (like quartz, emerald, and topaz). Looking for bubbles is one way to determine if a gem is glass or a gemstone.

Buccellati
Buccellati and Mario Buccellati are marks of Buccellati, Inc., a costume jewelry company that made intricate silver-colored pieces in ornate and modern styles.

Bud Leaf
The slang term given to the leaf of the cannabis plant, which is the plant used to make hemp products. It is a popular motif in modern jewelry. Also called a "marijuana leaf".

Buffalo Stone
See Ammolite.

Bugle Bead
A bugle bead is a long, thin, tube-shaped glass bead.

Bulla
A bulla is an ancient Roman pendant that consists of a rounded container holding an amulet (a good luck charm). The bulla is worn on a strap around the neck.

Burnish setting
A setting in which the gem is set flush with the setting's surface without using prongs to hold it in place.

Buttercup setting
A deep six prong setting with prongs that flare from the scalloped looking base resembling a buttercup flower.

Butterfly Chain
A chain composed of very tiny butterfly-shaped links with oval-shaped "wings". The butterflies are linked head to tail at a slight angle very close to one another so that the wings form a long continuous spiral along the length of the chain.

Butterfly clutch
A fitting that slides onto the back of an earring post to secure it in place.

Butterfly wing
Butterfly wing jewelry is made from real butterfly wings. A picture is usually painted on the wings, which is then enclosed in glass or plastic and then mounted in metal to make a pin, pendant, or other piece of jewelry.

Button
A method of joining two parts of a garment together by means of a toggle fastened to one side of the garment which is then pushed through a slit in the other side of the garment. The toggle, called a "button", is usually a disk and may be quite ornamental. Some buttons are worn strictly as decoration rather than serving a functional purpose. The term "button" is also applied to round pins that usually bear a slogan of some kind.

Button Earring
An earring with no dangling parts.

Byzantine Chain
An intricately designed chain. Two pairs of oval-shaped links are linked together. Each pair is then parted to allow a large thick oval link to be attached to the other pair.