Jewellery Glossary: Essential Terms Every Buyer Should Know

The world of jewellery comes with its own rich vocabulary. Whether you are browsing diamonds, selecting gemstones, or comparing precious metals, understanding the terminology used by jewellers and grading laboratories is essential for making confident, informed purchases. Misunderstanding a single term can lead to overpaying or choosing a piece that does not meet your expectations.

This glossary covers the most important terms you will encounter when shopping for jewellery, organised alphabetically for easy reference. Each definition is written in plain language so that even first-time buyers can quickly grasp the concepts. Bookmark this page and return to it whenever you encounter an unfamiliar term.

A

Akoya Pearl

A type of saltwater cultured pearl produced by the Pinctada fucata oyster, primarily farmed in Japan and China. Akoya pearls are prized for their exceptional lustre and near-perfect round shape. They typically range from 2 to 10 millimetres in diameter and are among the most classic and widely recognised pearls in jewellery.

Alloy

A mixture of two or more metals combined to improve strength, durability, or colour. Pure gold, for example, is too soft for everyday jewellery, so it is alloyed with metals such as copper, silver, or zinc to create more durable forms like 14k and 18k gold. The specific metals used in the alloy determine characteristics such as colour and hardness.

Asscher Cut

A square step-cut diamond shape with cropped corners, originally designed by Joseph Asscher in 1902. The Asscher cut features a distinctive hall-of-mirrors effect created by its large, open facets. It is sometimes described as a square emerald cut and is particularly popular in Art Deco-inspired jewellery.

B

Baguette

A rectangular step-cut gemstone with straight, clean lines and fewer facets than brilliant cuts. Baguette stones are frequently used as accent stones alongside a larger centre stone, particularly in engagement rings and eternity bands. The name derives from the French word for a long, narrow loaf of bread.

Bail

The metal loop or clasp at the top of a pendant that attaches it to a chain or cord. Bails come in various styles, from simple fixed loops to more elaborate hinged or enhancer designs that allow the pendant to be easily added or removed from different chains.

Bezel Setting

A setting style in which a thin strip of metal is wrapped around the entire circumference of a gemstone, holding it securely in place. Bezel settings offer excellent protection for the stone and create a sleek, modern appearance. They are particularly practical for active wearers, as the metal rim shields the stone from knocks and impacts.

Brilliance

The white light reflected from the surface and interior of a gemstone, particularly a diamond. Brilliance is one of the primary visual properties that make diamonds desirable and is largely determined by the quality of the cut. A well-cut diamond maximises brilliance by reflecting light efficiently through the crown.

Briolette

An elongated, pear-shaped gemstone cut covered entirely in triangular facets, with no flat top (table) or flat bottom. Briolettes are typically drilled at the narrow end and suspended as pendants or earring drops. This cut dates back centuries and is favoured for its exceptional sparkle when it catches the light from all angles.

C

Cabochon

A gemstone that has been shaped and polished into a smooth, rounded dome rather than cut with facets. Cabochon cuts are commonly used for opaque or translucent stones such as opals, turquoise, and jade, as well as stones that display optical phenomena like cat's eye or star effects. The smooth surface best showcases these unique properties.

Carat

The standard unit of weight for gemstones, equal to 200 milligrams (0.2 grams). One carat is divided into 100 points, so a 0.50-carat diamond may be referred to as a fifty-pointer. It is important not to confuse carat (gemstone weight) with karat (gold purity). Learn more in our diamond carat guide.

Channel Setting

A setting technique in which gemstones are placed side by side in a groove or channel between two parallel strips of metal, with no metal separating the individual stones. Channel settings create a smooth, continuous line of stones and are popular in wedding bands and eternity rings. The stones are held securely without prongs, reducing the risk of snagging.

Clarity

A measure of the internal and external imperfections (inclusions and blemishes) present in a gemstone, particularly a diamond. The GIA diamond clarity scale ranges from Flawless (FL) to Included (I3). Clarity significantly affects a stone's value, though many inclusions are invisible to the naked eye.

Cleavage

The tendency of a crystalline mineral to split along specific planes of weakness determined by its atomic structure. Diamonds, despite being the hardest natural material, have four directions of cleavage, which is why they can be split by a skilled cutter. Understanding cleavage is important for both cutting and setting gemstones safely.

Crown

The upper portion of a faceted gemstone, located above the girdle and below the table. The crown contains a series of angled facets that help refract light entering the stone, contributing to its brilliance and fire. Crown angle is one of the key proportions assessed in diamond cut grading.

Culet

The small facet or point at the very bottom of a faceted gemstone. In modern diamond cutting, the culet is typically very small or pointed (described as "none" on grading reports), as a large culet can create a visible dark spot when viewed from above. Antique diamonds often have larger, more noticeable culets.

Cushion Cut

A gemstone cut combining a square or rectangular outline with rounded corners, resembling a pillow or cushion. The cushion cut has been popular for over a century and features larger facets that produce broad flashes of light. It is available in both modified brilliant and classic variations, each offering a different pattern of sparkle.

D

Depth Percentage

The total depth of a diamond (from table to culet) expressed as a percentage of its average girdle diameter. Depth percentage is a key indicator of cut quality, as it affects how light travels through the stone. Diamonds with depth percentages that are too shallow or too deep will leak light and appear less brilliant.

Diamond Certificate

A document issued by an independent gemological laboratory that details the characteristics of a diamond, including the four Cs, measurements, proportions, and any treatments. Also known as a grading report or dossier. Certificates from respected laboratories such as GIA and AGS are considered the most reliable. Learn more in our certification guide.

Dispersion (Fire)

The splitting of white light into its component spectral colours as it passes through a gemstone. In diamonds, this optical property creates the rainbow flashes of colour known as fire. Dispersion is distinct from brilliance (white light reflection) and scintillation (sparkle), and together these three properties define a diamond's visual performance.

E

Emerald Cut

A rectangular step-cut gemstone shape with cropped corners and long, narrow facets arranged in parallel rows. The emerald cut was originally developed for cutting emeralds (hence the name) but is widely used for diamonds and other gemstones. Its open, transparent appearance emphasises clarity over brilliance.

Eternity Band

A ring featuring gemstones set continuously around the entire circumference of the band, symbolising everlasting love. Full eternity bands have stones all the way round, while half eternity bands feature stones across the front half only. They are popular as wedding rings, anniversary gifts, and stackable bands.

Eye-Clean

An informal industry term describing a gemstone whose inclusions are not visible to the unaided eye when viewed face-up at a normal viewing distance (approximately 25 centimetres). An eye-clean diamond offers excellent value, as it appears flawless to the casual observer despite having inclusions visible under magnification.

F

Facet

A flat, polished surface on a cut gemstone. The arrangement, number, and angles of facets determine how light interacts with the stone, affecting its brilliance, fire, and scintillation. A standard round brilliant diamond has 57 or 58 facets, while other cuts may have more or fewer.

Filigree

A delicate metalworking technique in which fine threads or beads of metal are twisted and soldered together to create intricate, lace-like decorative patterns. Filigree is a hallmark of vintage and antique jewellery and requires exceptional craftsmanship. Modern filigree is sometimes created using casting techniques that replicate the traditional handmade appearance.

Fluorescence

The visible light emitted by some gemstones when exposed to ultraviolet (UV) radiation. Approximately 25 to 35 per cent of diamonds exhibit some degree of fluorescence, most commonly blue. Strong fluorescence can sometimes cause a diamond to appear hazy, though in many cases it has no negative visual impact and may even improve the perceived colour of lower-colour diamonds.

Four Cs

The four primary characteristics used to evaluate diamond quality: cut, colour, clarity, and carat weight. Developed by the GIA, the four Cs system provides a universal language for describing and comparing diamonds. Of the four, cut has the greatest impact on a diamond's visual beauty. Explore each in detail: cut, colour, clarity, and carat.

G

GIA

The Gemological Institute of America, widely regarded as the world's foremost authority on diamonds, coloured gemstones, and pearls. Founded in 1931, the GIA created the four Cs grading system and the International Diamond Grading System. A GIA grading report is considered the gold standard for diamond certification.

Girdle

The narrow band around the widest circumference of a faceted gemstone, forming the boundary between the crown (top) and pavilion (bottom). The girdle may be faceted, polished, or left unpolished (bruted). Its thickness affects the stone's durability and overall proportions and is assessed as part of cut grading.

Gold-Filled

A layered metal product in which a thick layer of gold is mechanically bonded to a base metal core, typically brass. Gold-filled jewellery must contain at least five per cent gold by weight and is significantly more durable than gold-plated jewellery. With proper care, gold-filled pieces can last for decades without the gold layer wearing through.

Gold-Plated

Jewellery made from a base metal that has been coated with a thin layer of gold through electroplating. The gold layer in gold-plated jewellery is typically very thin (less than 0.5 microns) and will eventually wear away with use, exposing the base metal beneath. It offers the appearance of gold at a fraction of the cost.

H

Hallmark

An official mark stamped onto precious metal jewellery by an independent assay office, certifying the metal's purity. In the United Kingdom, hallmarking is a legal requirement for gold, silver, platinum, and palladium items above certain weight thresholds. A hallmark typically includes the sponsor's mark, the fineness (purity), the assay office mark, and sometimes the date letter.

Halo Setting

A ring setting in which a centre stone is encircled by a ring of smaller diamonds or gemstones. The halo creates the illusion of a larger centre stone and adds significant sparkle. Double halos, which feature two concentric rings of accent stones, amplify this effect further. Halo settings are among the most popular styles for engagement rings.

Heat Treatment

A common gemstone enhancement in which stones are heated to high temperatures to improve their colour, clarity, or both. Heat treatment is widely accepted in the jewellery trade and is used on many gemstones, including sapphires, rubies, and tanzanite. Untreated stones of fine quality command significantly higher prices.

HPHT

High Pressure High Temperature, a method used both to create laboratory-grown diamonds and to enhance the colour of natural diamonds. The HPHT process replicates the extreme conditions under which natural diamonds form deep within the Earth. When used for enhancement, HPHT can convert brownish diamonds to colourless or fancy colours.

I

IGI

The International Gemological Institute, one of the world's largest independent gemological laboratories. Established in 1975 in Antwerp, IGI operates laboratories across the globe and grades both natural and laboratory-grown diamonds. While well-respected, some industry professionals consider IGI grading slightly more lenient than GIA for certain characteristics.

Inclusion

An internal characteristic or imperfection within a gemstone, such as a crystal, feather, cloud, or needle. Inclusions are natural features formed during the stone's growth and are used to assess clarity. While most inclusions are microscopic, larger or more numerous inclusions can affect a stone's beauty and structural integrity.

J

Jardin

A French word meaning "garden," used to describe the characteristic internal inclusions visible in emeralds. These inclusions often resemble tiny plant-like or mossy patterns and are considered an identifying feature of natural emeralds rather than a defect. A fine emerald's jardin gives it a unique character and confirms its natural origin.

K

Karat

A unit of measurement indicating the purity of gold, expressed as parts per 24. Pure gold is 24 karat (24k), meaning all 24 parts are gold. 18k gold contains 18 parts gold and 6 parts other metals, making it 75 per cent pure. Do not confuse karat (gold purity) with carat (gemstone weight). See our guide on 18k versus 14k gold for a detailed comparison.

L

Lab-Grown Diamond

A diamond produced in a laboratory using either the HPHT or CVD (Chemical Vapour Deposition) process, possessing the same chemical, physical, and optical properties as a natural diamond. Lab-grown diamonds are typically 30 to 70 per cent less expensive than their natural counterparts. They are graded using the same criteria and are virtually indistinguishable without specialised equipment.

Loupe

A small magnifying lens used by jewellers and gemologists to examine gemstones and jewellery at close range. The standard jeweller's loupe provides 10x magnification, which is the magnification used for diamond clarity grading. Learning to use a loupe effectively can help buyers spot inclusions, assess settings, and evaluate craftsmanship.

Lustre

The quality and intensity of light reflected from the surface of a gemstone or pearl. Lustre is distinct from brilliance, which refers to light returned from within the stone. Pearls are particularly valued for their lustre, with high-quality specimens displaying a deep, mirror-like sheen. Metallic lustre, vitreous (glass-like) lustre, and waxy lustre are among the common types.

M

Marquise

An elongated gemstone cut with pointed ends, resembling a boat or an eye. The marquise cut maximises carat weight, making the stone appear larger than other cuts of the same weight. It is said to have been commissioned by King Louis XV of France to resemble the smile of the Marquise de Pompadour. Also known as the navette cut.

Melee

Small diamonds, typically under 0.20 carats, used as accent stones in jewellery settings. Melee diamonds are commonly found in halo settings, pave designs, and channel-set bands. They may be full-cut (with 57 or 58 facets) or single-cut (with 17 or 18 facets), depending on their size and the desired effect.

Mohs Scale

A relative scale of mineral hardness ranging from 1 (talc, softest) to 10 (diamond, hardest), developed by Friedrich Mohs in 1812. The scale measures a mineral's resistance to scratching. It is widely used in the jewellery industry to indicate a gemstone's durability and suitability for different types of jewellery. Explore the full scale in our gemstone hardness chart.

Mounting

The metal framework of a piece of jewellery into which gemstones are set. Also referred to as the setting or finding. The mounting includes the head (which holds the stone), the shank (the band of a ring), and any decorative elements. Mountings are available in various metals and styles, and the choice of mounting significantly affects both the appearance and security of the gemstone.

N

Nacre

The lustrous substance secreted by molluscs that forms the outer coating of pearls, also known as mother-of-pearl. Nacre is composed of microscopic layers of aragonite (a form of calcium carbonate) bound by an organic compound called conchiolin. The thickness and quality of nacre directly determine a pearl's lustre, durability, and overall value.

O

Old Mine Cut

A diamond cutting style prevalent from the early eighteenth century through the late nineteenth century, characterised by a cushion-shaped outline, high crown, small table, and large culet. Old mine cut diamonds were cut by hand and optimised for candlelight rather than modern electric lighting. They are highly sought after by collectors and those who appreciate antique jewellery.

Oxidation

A chemical reaction in which a metal combines with oxygen, often resulting in a change of colour or the formation of a surface coating. In jewellery, oxidation is most commonly associated with silver tarnishing, though it can affect other metals as well. Some jewellers deliberately oxidise silver to create a darkened, antiqued appearance.

P

Pave

A setting technique in which numerous small gemstones are set closely together with minimal visible metal, creating the appearance of a continuous surface of stones. The name comes from the French word for "paved," as the stones resemble a cobblestone street. Micro-pave uses even smaller stones set with the aid of a microscope for an exceptionally delicate effect.

Pavilion

The lower portion of a faceted gemstone, extending from the girdle down to the culet. The pavilion's facets are angled to reflect light back up through the crown to the viewer's eye. The pavilion angle is one of the most critical proportions in diamond cutting, as even small deviations can cause significant light leakage.

Plating

The process of depositing a thin layer of one metal onto the surface of another, typically through electroplating. Common examples in jewellery include gold plating over base metals and rhodium plating over white gold. Plating enhances appearance but is not permanent and will need to be reapplied over time as it wears.

Princess Cut

A square or slightly rectangular brilliant-cut gemstone shape, viewed from above. The princess cut is the second most popular diamond shape after the round brilliant and is favoured for its modern, geometric appearance and excellent brilliance. Its pointed corners are sometimes prone to chipping and should be protected by the setting.

Prong Setting

The most common gemstone setting, in which thin metal claws (prongs) grip the stone at its girdle, holding it in place while allowing maximum light to enter. A standard prong setting uses four or six prongs. Fewer prongs show more of the stone but offer less security, while more prongs provide greater protection at the cost of slightly more metal visibility.

R

Radiant Cut

A rectangular or square gemstone cut that combines the elegant outline of an emerald cut with the brilliance of a round brilliant. The radiant cut features cropped corners and a complex facet pattern that produces exceptional sparkle. It is a versatile choice that works well as a centre stone in both modern and classic ring designs.

Rhodium Plating

The application of a thin layer of rhodium (a rare platinum-group metal) to jewellery, most commonly white gold, to enhance its whiteness, brightness, and scratch resistance. Rhodium plating is not permanent and will eventually wear away, revealing the slightly yellowish colour of white gold beneath. Replating is a routine maintenance procedure for white gold jewellery.

S

Scintillation

The flashes of light and dark that appear when a diamond, the light source, or the observer moves. Often described as sparkle, scintillation is one of the three main visual properties of a diamond alongside brilliance and fire. A well-cut diamond displays a balanced pattern of scintillation with neither too few large flashes nor too many tiny ones.

Setting

The method by which a gemstone is secured within a piece of jewellery. Common setting types include prong, bezel, channel, pave, tension, and flush settings. The choice of setting affects the stone's security, visibility, and overall aesthetic. Different settings suit different lifestyles and gemstone types.

Solitaire

A jewellery design featuring a single gemstone, most commonly used in engagement rings. The solitaire setting showcases the stone without distraction and remains the most popular engagement ring style worldwide. Despite its simplicity, the solitaire can be rendered in numerous variations by changing the setting type, band profile, and metal choice.

Sterling Silver

An alloy consisting of 92.5 per cent pure silver and 7.5 per cent other metals, typically copper. Sterling silver is marked with the hallmark 925 and is the standard for silver jewellery and silverware. Pure silver is too soft for practical use, so the addition of copper provides the necessary hardness and durability. Learn more about the 925 hallmark.

Symmetry

In diamond grading, symmetry refers to the precision of a stone's outline, the alignment and placement of its facets, and the evenness of its proportions. Symmetry is graded from Excellent to Poor and affects how light interacts with the diamond. Diamonds with excellent symmetry display more uniform and attractive patterns of light return.

T

Table

The largest facet on a cut gemstone, located at the very top of the crown. The table is the primary window through which light enters and exits the stone. Table percentage (the table width relative to the diamond's diameter) is a key proportion in cut grading, as it influences the balance between brilliance and fire.

Tarnish

A thin layer of corrosion that forms on the surface of certain metals, particularly silver, when they react with sulphur compounds in the air or on the skin. Tarnish appears as a dull, darkened film and can be removed with appropriate cleaning methods. Learn how to prevent and treat tarnish in our guides on preventing tarnish and why silver tarnishes.

Tennis Bracelet

A flexible bracelet consisting of a single row of individually set diamonds or gemstones linked together in a continuous line. The name originated in 1987 when tennis player Chris Evert's diamond bracelet broke during a match, and she paused play to retrieve it. Tennis bracelets are a classic jewellery staple and are available in a wide range of carat weights and settings.

Tension Setting

A modern setting technique in which the gemstone is held in place by the pressure (tension) of the metal band pressing against opposite sides of the stone. The result is the striking illusion that the stone is floating between the two ends of the band. Tension settings require precise engineering and are best suited to hard gemstones such as diamonds and sapphires.

Troy Ounce

The standard unit of weight used for precious metals, equal to approximately 31.1 grams. A troy ounce is slightly heavier than a standard (avoirdupois) ounce, which equals approximately 28.3 grams. Gold, silver, platinum, and palladium are all priced and traded internationally by the troy ounce.

V

VS (Very Slightly Included)

A diamond clarity grade indicating that the stone contains minor inclusions that are difficult to see under 10x magnification. The VS range is divided into VS1 (fewer or less visible inclusions) and VS2. VS diamonds are typically eye-clean and represent an excellent balance of quality and value for most buyers.

VVS (Very, Very Slightly Included)

A diamond clarity grade indicating that the stone contains minute inclusions that are extremely difficult to detect even under 10x magnification. The VVS range is divided into VVS1 and VVS2. While these diamonds are virtually flawless to the naked eye, the premium over VS grades is significant and may not represent the best value for all buyers.

W

White Gold

A gold alloy created by combining pure gold with white metals such as palladium, nickel, or silver to produce a silvery-white colour. White gold is typically plated with rhodium to enhance its whiteness and protect against scratching. It offers a similar appearance to platinum at a lower price point, though it requires periodic replating to maintain its bright finish.

Conclusion

Understanding jewellery terminology empowers you to communicate confidently with jewellers, interpret grading reports accurately, and make purchases that truly match your expectations. This glossary covers the most commonly encountered terms, but the world of jewellery is vast and continually evolving. Whenever you come across an unfamiliar word, do not hesitate to ask your jeweller for clarification or return to this guide.

For more in-depth exploration of these topics, browse our buying guides, diamond education section, and gemstone guides. The more you learn, the more rewarding your jewellery journey becomes.