Glossary of Jewellery Terms
There's nothing like a little techno babble or a few mysterious names to add a little status and cachet to a jeweller's conversation. So here is a glossary of jewellery terms you might come across. If there's any others you think we might include, let us know.
Pearls from the Akoya saltwater oyster which is the mainstay of the Japanese pearl industry. Now also farmed by China and other countries.
A chain with a T-bar fitting. These were originally attached to a pocket (or fob) watch, frequently with a decorative medallion or other ornament attached to one end. Due to the decrease in waistcoat wearing, ladies recycled their husband's or father's chains and wore these as fashionable necklets.
An alloy is a combination of two or more metals. Common alloys used in jewellery and giftware in the UK are:
Gold 9ct (37.5% gold with varying amounts of other metals such as silver depending on colour and other characteristics wanted) Gold 18ct (75% gold), 22ct (91.6% and very soft); Platinum (95% platinum); Silver Sterling (92.5% silver); and Pewter (92% tin with lead, antimony and a bit of silver or copper) .
As you work metal it becomes brittle. Heating and cooling it restores its malleability and ductility, enabling you work it again.
This is a gemstone cut in a narrow rectangular shape.
Baroque is a term that refers to irregularly shaped stones or pearls .
Irregular shaped pearls of all shapes and sizes, neither round nor symmetrical. The surface is usually uneven. Most are inexpensive, but some have come to be the centrepiece for very expensive pieces of jewellery .
A method of setting gemstones in which the stone is held in the mounting by a narrow band of metal surrounding the girdle (outside perimeter) of the stone.
A pearl necklace of more than three concentric strands.
Cultured freshwater pearls grown in Lake Biwa in Japan.
The oyster famous for the Tahitian pearl which is found in the South Pacific in and around Tahiti and French Polynesia.
A natural coloured dark pearl grown in the black-lipped oyster. The colour is black, light black/silvery or a dark grey, although other very dark colours such as the rarer peacock green are also referred to as black pearls. Natural colour black pearls are rare and most of the cheaper black pearls, especially freshwater, are dyed.
Little marks, bumps, scars or irregularities on a pearl's surface that give a pearl strand its personality, although heavy marking will lower its value.
In reality, a natural pearl which occurs when a parasite intrudes through the outer shell of a mollusc. The mollusc secretes nacre over the irritant, cementing it to the shell itself. Blister pearls are usually irregular in shape. See also Mabe pearls.
A dark-coloured pearl whose colour derives from foreign contaminants in the nacre, or between the nacre and the shell bead nucleus. Typically, blue pearls are naturally coloured dark Akoya pearls, which may be blue or other dark colours.
A faceted tear-drop shaped stone. If it is unfaceted it is a drop.
Also known as a scroll. It is the fitting that attaches to the post of an earring to hold it in your ear.
A stone cut with a domed top and a flat bottom. These are usually round or oval.
A style of carving in which the design motif is left and the surrounding surface is cut away, leaving the design in relief. Cameos are still made today in Italy.
A unit of weight measurement for precious stones . It is important not to confuse this with the other karat (American spelling) or carat, which is a measure of the purity of gold. 'Carat' is abbreviated to "ct." One carat is equal to 1/5 of a gram (200 milligrams). Stones are measured to the nearest hundredth of a carat. There are a hundred points in a carat, so that a .10 carat stone can also be described as a 10 point stone. Smaller stones are most often referred to by point designations.
An average one-carat round diamond usually measures approximately 6.5mm in diameter. This relationship of weight and size, however, is different for each type of cut and differs for other gems. Rubies and sapphires, for example, are both heavier than diamonds, so a one carat ruby or sapphire is smaller in size than a one carat diamond.
These closely resemble mini chandeliers. They are also known as shoulder dusters.
A setting in which several stones are held in by two parallel gold or other precious metal borders and in which there is no metal between the individual stones, giving the appearance that they are floating within the setting. This is a popular modern style setting for eternity rings.
From the French words chat (cat) and oeil (eye) and describes the optical effect whereby a strip of light is reflected within the stone and glints back and forth, resembling the feline eye. It is most prominent in chrysoberyl , but is also found in a few other gemstones including tourmaline .
A claw setting is one in which a series of metal prongs (called claws) holds a stone securely in a setting (the claws grips the stone just above the girdle of the stone), with no metal directly under the stone (it is an open setting). This setting lets light in under the stone, so this type of setting is usually used for transparent, faceted stones. The modern-day claw setting became popular in the 1800s.
A coronet setting (also called châton or arcade setting) is one in which the stone is held in by many metal claws around a metal ring.
The top half of a gemstone. This usually consists of a larger flat facet (called the Table) and smaller facets on the shoulders.
The Culet is a small facet on the very point of the Pavillion (the underside of a cut gemstone) to flatten the otherwise sharp point. This is partly to remove a feature that would have a tendency to scratch and also remove what would be a vulnerable point for the stone.
This can be a type of diamond cut incorporating both a round and square shape (therefore resembling a cushion). It also refers to a style of signet ring stamping, which is also cushion-like, being square with rounded corners.
Cuts (for gemstones)
Asscher- A square emerald cut developed in 1902
Baguette - A diamond cut, usually rectangular, but can also be tapered.
Brilliant - A 58 facet cut diamond. One of the most popular cuts today.
Cabochon - A cabochon is a stone that has a rounded, domed surface with no facets.
Emerald - A rectangular cut often used for emeralds (hence the name) but also for diamonds and other stones.
Marquise - A fancy "boat shaped" diamond cut. Oval, but with pointy ends.
Oval - Guess what shape?
Princess - A square-cut diamond equivalent to a brilliant cut. Also called a Quadrillion or Squarillion cut.
Radiant - A cross between a square emerald cut and a brilliant cut.
This is a very faintly carved surface decoration, which can also be created using acids or lasers.
A choker length formed from multi-strands of gems or pearls.
A stamping technique in which a pattern (for example a scroll pattern similar to an engraved effect) is pressed onto a plain area of metal to leave the pattern in relief, i.e. standing proud above the plain background rather than cut in as in the case of engraving.
This is the stepped, normally rectangular gemstone-cut with cropped corners.
Enamel is produced by fusing coloured powdered glass paste to metal (usually silver, copper or gold) to produce a glass-like, decorative surface. The colour of the enamel and its transparency depends on the metal oxides in the glass and the temperature at which the glass melts. In some cases, the enamel may be translucent showing the textures of any engraving on the metal underneath, which produces guilloche (pronounced ghee-yosh) enamel.
Another engraving technique that can be applied to plain metal, and is frequently used on powder compacts, cigarette lighters and larger pieces. Geometric, criss-cross designs are generally favoured.
This is gouging out a design in metal with graver's tools, or embellishing metal or other material with patterns using a drill. This was fashionable in mid-Victorian jewellery. The resulting depressions were often filled with coloured enamel. Engraving is also used for inscriptions. Chasing is where the surface of the metal is moved, but not actually carved out.
An eternity ring is a narrow ring with a line of diamonds or other gemstones running all the way round. The unbroken circle symbolising eternity. A husband often gives it to his wife after a number of years of marriage or the birth of a child to show that the commitment made at their wedding is as strong as ever.
A flat cut or polished face on a gemstone.
A faceted stone has small, flat-cut surfaces that make a sparkling effect on transparent stones. Facets act as both mirrors and windows. Reflecting light and channelling light into a stone where it refracts and re-emerges.
Fastenings - Bracelets & Necklaces
Bolt Ring - The basic type of fastening for a necklace or bracelet consisting of a hollow loop with an internal spring operated catch, which is retracted then released when attached to a link at the other end of the chain.
Jump Ring - This is a fixed ring used to connect components in a finished article, or at the end of items such as necklets and to which bolt rings may be attached.
Padlock - Looking just like a traditional padlock (but without a key), this fastening clicks into place and is commonly used on gate bracelets.
Pearl Fastener (Barrel) - Pearls are traditionally fastened by means of a clasp, one side of which screws into the barrel of the other.
Trigger - Also known as a karab or lobster claw clasp (one look at it shows why!), this is related to a bolt ring as it has a trigger which lifts a bar, allowing a jump ring or other loop to be inserted. It operates like a mountaineer's karabiner. This is a popular fastening for heavier chains. A Squared lobster claw clasp is similar but with parallel side edges.
Magnetic - A recent innovation using powerful mini magnets.
Other, more obscure, fastenings include the Box and the Ladder.
Fastenings - Earrings
There are a wide variety of earring fittings: -
Andralok - A patented pierced earring fitting with a hinge half way along the earring stem. After inserting the stem, the hinged section drops down behind your ear to hold the earring in place.
Andraslide - A patented earring fitting for un-pierced ears. A U-shaped spring fits under the ear lobe and round the back of the ear to hold the earring in place. Claimed to be more comfortable than traditional clips as it does not grip so tightly, is lighter and not so bulky on the ear.
Clip - A traditional hinged earring fitting for un-pierced ears.
Continental - See Lever back.
Hook fitting - Usually for drop earrings and also called a hook wire or safety wire fitting, these earring fittings hook through the ear and hang down behind the lobe. They have the advantage of not requiring butterflies, which can be fiddly or easy to lose, but are usually larger and more expensive. Safety wire fittings also have a snap shut closure for extra security.
Lever back - Usually for drop earrings, this is a type of hook fastening for pierced ears that utilises a hinged "lever" on the main part of the earring to close the gap to the end of the hook. Also called "Continental" due to its popularity in Europe.
Post and Butterfly - For stud or drop earrings and occasionally also called a "French Fitting", this is the commonest form of earring fastening for pierced ears using a 'post' attached to the earring, which connects with a separate scroll shaped device (butterfly) to hold the earring in place.
A term meaning imitation. For example, "faux pearls" is often used to describe simulated pearls.
Filigree is gold or silver wire that have been twisted into patterns and soldered into place. Openwork filigree is not soldered onto a sheet of metal and is difficult to make. Imitation filigree is made of stamped metal.
Fineness is the proportion of silver or gold in a metal alloy . Fineness is usually expressed in parts per thousand. For example, the fineness of sterling silver is 925.
Pearls predominantly flesh-nucleated typically in mussels in several countries around the world, notably China, Japan and the USA.
A setting with a recessed stone, also known as a star setting.
The girdle is the widest perimeter of a gemstone.
Though we don't use this technique, it is useful to be aware of it. 14k Gold Fill is not the same as gold plated. There is around 100 times more gold in gold fill than there is on plated wire. Gold filled looks like and usually wears as well as karat gold. Often referred to in the UK as rolled gold, Gold Fill is very hard wearing and unlike gold plating is unlikely to wear off, even with use. Gold-filled pieces must be at least 1/20 by weight in gold to be classified as gold-filled.
This is when transparent or at the very least translucent enamel is applied to metal which has detailed engraving on it. Pronounced 'ghee-yosh'.
A unit sometimes used to measure pearls - a metric or pearl grain is equal to 50 milligrams or ¼ of a carat.
This is a stamped mark applied to items of jewellery and silverware by the Assay Offices of Britain as a guarantee of authenticity. The mark consists of four components:
The sponsor (or manufacturer) mark; the standard mark, which denotes the precious metal content of the item; the Assay Office Mark (Assay Offices are found in London, Birmingham, Sheffield and Edinburgh) and the date letter which shows the year in which the article was hallmarked.
A particle of foreign matter contained within a gemstone. It can take, for example, the form of an air bubble or a foreign object. Some inclusions decrease the value of a stone, but some, such as needles in rutilated quartz and 'spangles' in amber, are prized.
This is when a space is routed out of the metal and a contrasting material is fitted into that space.
Italian for carving. An Intaglio is a carved gem from which the design is engraved or carved into the object so that it sits below the surface plane of the material. The opposite to a cameo which is carved in relief. Intaglio is used for signet rings and seals, to make a raised impression in the hot wax.
This is an optical phenomenon in which the hue on the surface of the stone changes according to the angle from which the surface is viewed. A similar phenomenon may be seen on the surface of soap bubbles and on butterfly wings. The word is derived in part from the Greek word iris, meaning 'rainbow', from the goddess Iris, the personification of the rainbow in Greek mythology.
In order not to confuse karat with "carat", Americans changed the spelling. We obtuse Brits still habitually use the same spelling and word for two different and easy to mix up jewellery terms. Carat is a measure of the weight of gemstones, whereas karat is a measure of the purity of gold. The ratio of gold to other metals is measured in 24 parts, called karats - hence 24 karat gold is pure gold, while, for example, 9 karat gold is 9 parts gold and 15 parts other metal.
These are small flat roundish natural pearls formed naturally in the soft cavities left after a pearl has been removed or ejected by the mollusc. They are 100% nacre and have a very good lustre.
Small knots tied between each pearl in a strand to prevent them rubbing together and to avoid the loss of pearls if the necklace breaks. Recommended for larger pearl necklaces.
A magnifying lens used by jewellers to closely study a gemstone or a hallmark. Gemologists generally use a 10x hand held loupe while jewellers working at the bench often use a 5x eyepiece.
The appearance/shininess of a pearl's surface judged by its ability to reflect light. One of the most important factors in judging and pricing pearls.
Formed when a half-bead is cemented to the mollusc's inner shell. The mollusc covers the half bead with nacre and when the shell is cut off, the bead is exposed at the back. The bead is removed, the pearl cleaned (to prevent deterioration) and the remaining hole filled with paste, wax or sometimes with another bead and then covered with a mother-of-pearl backing. Mabe pearls must only be used in closed-back settings. Also referred to as a half-pearl or cultured blister pearl.
A well-known type of imitation pearls from the Spanish island of the same name. Also known as Majorcan pearls, they are quite popular in the USA. Many people believe them to be real pearls when, in fact, they are high quality imitations.
The part of a mollusc's soft tissue that secretes nacre. This tissue is also used to nucleate and stimulate pearl formation in freshwater pearls.
A leading brand of pearls founded by Kokichi Mikimoto, the Japanese man credited as the creator of cultured pearls.
The smooth, hard pearly lining on the interior of oyster and mollusc shells, famous for buttons and small decorative objects. It is the same substance as nacre which forms pearls.
The pearly substance secreted by the mantle of certain molluscs to form a pearl.
Millegrain ("thousand grains")
A setting in which the stone is secured by many tiny beads (hence "mille grains") of metal. It also refers to a band of metal that is decorated with tiny beads of metal.
An oval stone which is pointed at both ends.
A metal that was frequently used in fashion jewellery and occasionally as an alloy in gold jewellery. However, some people have an allergy or skin reaction to nickel which results in a rash, particularly if worn as pierced jewellery such as earrings. Recent European legislation (the Nickel Directive) strictly defines the amount of nickel that jewellery can contain, to ensure that it remains far below the level at which such skin reactions could become likely.
Typically refers to freshwater pearls whereby mantle tissue from another mollusc is inserted to stimulate pearl growth. Refers to tissue-nucleated pearls.
A nucleus is inserted into a mollusc to speed up the pearl growth. Acting as the irritant, the nuclei is covered by nacre.
Opalescence is a type of dichroism where a gem appears yellowish-red in transmitted light and blue in the scattered light perpendicular to the transmitted light. The phenomenon is named after the appearance of opals. This effect can be seen in nature in the way the sky is blue in the daytime and yellowish-red at sunset.
The pearly lustre seen on pearls or mother-of-pearl shells. Also known as irridescence.
Natural pearls found in the waters of the Persian Gulf. Due to pollution, production is almost non-existent nowadays.
Ounce & Troy Ounce
Pre metric measures are still used in many areas of gold and silversmithing. The Troy ounce (about 10% heavier than an Imperial or avoirdupois ounce) was and is used for precious metals. 1ozt is 480 grains. A grain being the weight of a grain of barley taken from the middle of the ear. Simple.
Patina is the natural effect of use and age on a surface. Tiny, almost imperceptible scratches eventually merge to form a new lustrous finish. A rich patina on fine sterling silver and gold enhances its beauty over time.
Stones set close together, showing no metal between them .
The pavilion is the top section of a gemstone above its widest point (the girdle).
Pearl Necklace Lengths
A word that describes the appearance of a gemstone or a finish e.g. a knife handle that reflects light in a pearl-like way, but which is not necessarily a pearl. A pearlescent look generally has an illusory depth to it, seemingly of different layers of semi-transparent white and off-white coatings. The appearance of Mother of Pearl is also described as pearlescent.
An effect where the properties of diffraction in a stone cause it to look a different colour depending on the angle you observe it from. Many stones are dichroic or trichroic.
Plique a Jour
Literally 'glimpse of day'. Transparent coloured enamel windows which allow the passage of light.
Rhodium is a transition element, belonging to the platinum group of metals. Rhodium plating is silvery-white in colour and used to both harden the surface it covers, and to create a brighter, more polished look to gold, especially white gold. Gemstones then show to their best effect and the claws holding the gems are firmer and less likely to damage. Rhodium plated jewellery is extremely hard wearing, tarnish resistant and will not be affected by body enzymes, perfumes and hair sprays, helping it to look good for years to come.
Rolled Gold (see Gold Filled)
This is a traditional process invented in the 19th century in which a sheet of gold is laminated to a base metal (usually brass). The two layers of metal are heated under pressure to fuse them together. This is then rolled to make a thinner sheet, which can be used to make jewellery or other objects. Although not solid gold, this method produces items that wear well over time.