Jewellery Glossary
The terms you'll actually meet when buying, wearing, or inheriting a piece — defined in plain English, and linked to the deeper guides where there's more to know.
51 terms
A
- AlloyMetals
- A blend of a precious metal with others to add strength or change colour — pure gold and silver are too soft for most jewellery.
- AssayMarks & trade
- The testing of a metal to determine its precious-metal content. Hallmarks →
- Assay officeMarks & trade
- An independent body that tests precious metal and strikes its hallmark. Hallmarks →
B
- BaroquePearls
- An irregularly, often dramatically shaped pearl.
- Base metalMetals
- A non-precious metal such as copper, brass, or nickel, used as a core or in costume jewellery.
- Bezel settingSettings & technique
- A metal rim that surrounds and secures a stone — protective and modern-looking.
- BirthstoneGemstones
- A gemstone traditionally associated with a month of birth. Birthstones guide →
- BlemishGemstones
- A surface imperfection on a gemstone, such as a scratch or nick.
- BrillianceDiamonds
- The white light reflected back out of a diamond. The 4Cs →
- Brilliant cutDiamonds
- A faceting style — most famously the 57–58-facet round brilliant — designed to maximise brilliance.
- Britannia silverMetals
- A higher silver standard, 95.8% pure, marked 958 — softer and rarer than sterling. Hallmarks →
C
- CabochonGemstones
- A gem cut as a smooth, rounded dome rather than faceted — common for opals and star stones.
- Carat (weight)Diamonds
- A gem's weight: one carat is 0.20 grams, divided into 100 points. The 4Cs →
- Channel settingSettings & technique
- Stones set in a row within a channel of metal, with no prongs between them.
- ClarityDiamonds
- How few and faint a stone's inclusions and blemishes are, graded Flawless (FL) down to Included (I3). The 4Cs →
- Colour (grade)Diamonds
- How colourless a white diamond is, graded D (colourless) to Z (light yellow or brown). The 4Cs →
- Common Control Mark (CCM)Marks & trade
- The international Convention hallmark — a set of balance scales — recognised across member states. Hallmarks →
- CuletDiamonds
- The tiny facet — or point — at the very bottom of a cut stone.
- Cultured pearlPearls
- A pearl grown by deliberately inserting a nucleus into a mollusc — most pearls sold today.
- CutDiamonds
- How well a stone is proportioned and faceted, which governs its sparkle. Not the same as its shape. The 4Cs →
F
- FiligreeSettings & technique
- Delicate openwork made from fine twisted wire.
- FinenessMetals
- Purity in parts per thousand (750 = 75%). The universal measure struck on a hallmark. Hallmark Calculator →
- FireDiamonds
- The flashes of rainbow colour a diamond disperses from white light. The 4Cs →
G
- GirdleDiamonds
- The thin band around the widest part of a stone, separating the crown from the pavilion.
- Gold platingMetals
- A thin layer of gold deposited (often electroplated) onto base metal; wears faster than gold-filled.
- Gold-filledMetals
- A thick layer of gold mechanically bonded to a base metal — far more durable than plating, with legal minimum thickness.
H
- HallmarkMarks & trade
- Official marks struck on precious metal certifying its fineness, its maker, and (where applicable) the assay office. Hallmarks →
I
- InclusionGemstones
- A natural feature trapped inside a gemstone as it formed.
K
- Karat (gold)Metals
- Gold purity in 24ths: 24K is pure, 18K is 18/24 (75%) gold. Not to be confused with carat, the gem weight. Hallmark Calculator →
L
- Lab-grownGemstones
- A gem grown in a laboratory with the same composition and properties as its natural counterpart; should be disclosed.
- LustrePearls
- The depth and sharpness of the reflections on a pearl's surface — the key to its quality.
M
- MilgrainSettings & technique
- A decorative border of tiny beads of metal along an edge.
- Mohs scaleGemstones
- A 1–10 ranking of a mineral's scratch-hardness — talc is 1, diamond is 10. A guide to how a stone wears.
N
- NacrePearls
- Mother-of-pearl — the iridescent substance a mollusc layers to form a pearl's surface.
P
- PalladiumMetals
- A light, naturally white platinum-group metal; hallmarked in the UK since 2010. Hallmarks →
- PavéSettings & technique
- Many small stones set closely together so the surface looks paved with gems.
- PlatinumMetals
- A dense, naturally white and hypoallergenic precious metal, usually used at 950 fineness. Hallmarks →
- Precious vs semi-preciousGemstones
- A traditional, loose split; 'precious' historically meant diamond, ruby, sapphire, and emerald.
- Prong settingSettings & technique
- Metal claws that grip a stone and let in the most light; also called a claw setting.
R
- RepousséSettings & technique
- Relief decoration hammered into metal from the reverse side.
- Rhodium platingMetals
- A bright, hard plating of a platinum-group metal, used to whiten and protect white gold.
- Rose goldMetals
- Gold alloyed with copper for a warm pink hue.
S
- ScintillationDiamonds
- The play of sparkle — light and dark flashes — as a stone or the light moves.
- SolderSettings & technique
- A metal alloy used to join parts of a piece; its presence widens the legal hallmark tolerance.
- Sponsor's markMarks & trade
- The registered mark identifying the maker or company that submitted a piece for hallmarking; also called a maker's mark. Hallmarks →
- Sterling silverMetals
- The standard silver alloy, 92.5% pure, marked 925. Hallmarks →
T
- TableDiamonds
- The large flat facet on the top of a cut stone.
- The 4CsDiamonds
- Cut, colour, clarity and carat — the four factors that set a diamond's quality, graded the same way worldwide. The 4Cs →
- TreatmentGemstones
- Any process — heat, oil, irradiation — that improves a gem's appearance. Reputable sellers disclose it.
V
- VermeilMetals
- Sterling silver coated with a thick layer of gold (in the US, at least 10K and 2.5 microns).
W
- White goldMetals
- Gold alloyed with white metals (e.g. palladium or nickel) and usually rhodium-plated for whiteness.