Bullion glossary
A-Z reference of every term used across this site and the wider UK bullion market. Hover any letter to jump to it; many entries link to a longer article in the /learn hub.
A
- Allocated storage
- Vault storage where specific bars belong to you, are identified by serial number, and sit outside the storage company's balance sheet. If the vault company goes bankrupt, your bars are still yours. Read more →
- Assay
- The formal test that determines a precious metal's purity. Refiners assay every bar before stamping fineness; UK assay offices hallmark gold and silver.
- Assay card
- Tamper-evident packaging that seals a small minted bar with its certificate of authenticity (e.g. PAMP Veriscan, Royal Mint DNA Certified).
- Avoirdupois ounce (oz)
- The everyday ounce — 28.349523125 grams. Used for food, postage and almost everything except precious metals. Read more →
B
- Baht
- Thai gold unit — 15.244 grams gross, typically 96.5% pure (so ~14.71g fine gold per baht). Read more →
- Bid-ask spread
- The difference between a dealer's buy and sell prices on the same item. Wider spread = more expensive dealer. Read more →
- Britannia silver
- The historical UK silver standard at 958.4 fineness (separate from modern Royal Mint Britannia 999 silver coins, which are pure).
- BU (Brilliant Uncirculated)
- A premium-bullion finish that's a step above standard bullion but below proof. Specially prepared blanks, sealed in card or capsule. Read more →
- Bullion
- Gold, silver, platinum or palladium in bar or coin form, valued by metal content rather than rarity or design.
C
- Cast bar
- A bar poured into a mould and cooled. Cheaper to produce than minted bars; typical at 100g+ sizes. Read more →
- CGT (Capital Gains Tax)
- UK tax on profit when you sell most investment assets. Legal-tender UK coins (Sovereign, Britannia) are exempt for UK residents. Read more →
- Coin silver
- Historical silver standard at 900 fineness. Used in many pre-1965 US silver coins.
- CombiBar
- A Valcambi bar with perforated 1g (gold) or 1g (silver) segments that snap apart, sold as a single piece with built-in divisibility.
- Crown (mark)
- Historical UK hallmark indicating gold, now largely obsolete. Modern UK gold uses fineness numbers.
D
- Date letter
- The single letter in a UK hallmark indicating the year the piece was assayed. Each office has its own letter cycle. Read more →
- Dealer spread
- The gap between a dealer's sell price and their buy-back price on the same item. The dealer's effective trading profit.
F
- Fine gold
- Gold that's at least 999 fine (99.9% pure). Required minimum for HMRC investment-gold VAT exemption is 995.
- Fineness
- A metal's purity expressed in parts per thousand. 999 = 99.9% pure; 925 = 92.5% sterling silver; 916 = 91.67% (22-carat gold). Read more →
G
- Good Delivery
- The LBMA's accreditation for refiners that meet strict purity and consistency standards. Good Delivery bars trade institutionally without re-assay. Read more →
- Grain (gr)
- The smallest practical bullion weight unit — 0.0648 grams. 480 grains = 1 troy ounce. Read more →
H
- Hallmark
- Marks struck onto UK gold, silver, platinum and palladium indicating sponsor, fineness, assay office and year. Read more →
K
- Karat (carat)
- Gold purity on a 24-point scale. 24k = pure gold; 22k = 916 fine (Sovereign); 18k = 750 fine (jewellery). Read more →
L
- LBMA
- London Bullion Market Association — the wholesale trading body whose Good Delivery standard underpins global gold and silver markets. Read more →
- LBMA Gold Price / Silver Price
- Auctioned reference prices set twice a day in London (formerly the 'fix'), used as the institutional benchmark.
- Legal tender
- A coin recognised by law as currency. UK Sovereigns and Britannias are legal tender, which is why they're CGT-free for UK residents.
- Leopard's head
- The London Assay Office mark — a leopard's head with crown. Read more →
- Lion Passant
- Historical UK silver hallmark indicating sterling (925) silver. Optional since 1999 but still common.
M
- Mace
- Hong Kong / Chinese gold unit — 3.78 grams. Read more →
- Margin scheme
- UK VAT scheme where second-hand silver coins are sold with VAT charged only on the dealer's margin, not the full price. Read more →
- Millesimal fineness
- Purity expressed in parts per thousand — e.g. 999 = pure, 925 = sterling. Read more →
- Minted bar
- A bar struck from blanks with engraved dies — like a coin. Pristine finish, sealed in an assay card. Standard at 1g–1oz sizes. Read more →
N
- Numismatic premium
- Premium paid above metal value for collector interest — rarity, condition, historical significance.
P
- Pennyweight (dwt)
- 1.555 grams; 20 dwt = 1 troy ounce. Still used by US jewellery scrap dealers. Read more →
- Premium
- What you pay above spot — covers refiner fabrication, mint margin and dealer margin. Varies from ~2% (1kg cast bar) to 25%+ (1g minted bar). Read more →
- Proof
- The highest coin finish — mirror fields and frosted designs from multiple strikes onto polished blanks. Comes with COA in presentation case. Read more →
- Purity
- What fraction of the piece is the named metal. Expressed as karat, fineness number, or percentage. Read more →
S
- Sigma verifier
- Hand-held device that tests electrical conductivity to verify a bar isn't a tungsten-cored fake. Standard dealer tool. Read more →
- Sovereign
- UK 22-carat gold legal-tender coin — 7.32g fine gold, £1 face value. CGT-free for UK residents. Read more →
- Sponsor's mark
- The two-letter mark in a UK hallmark identifying the maker or importer. Read more →
- Spot price
- The wholesale benchmark price of pure metal per troy ounce. The reference; not the price you'll pay at a dealer. Read more →
- Sterling silver
- 925 fine silver (92.5% pure). The standard for UK silverware and silver jewellery.
T
- Tola
- Indian / South Asian gold unit — 11.6638 grams. Standard for gold trading across India, Pakistan and the Gulf. Read more →
- Troy ounce (oz t)
- The bullion-market standard ounce — 31.1034768 grams. About 10% heavier than the everyday avoirdupois ounce. Read more →
- Troy pound
- Historical precious-metals pound — 12 troy ounces = 373.24g (lighter than a supermarket pound).
U
- Unallocated storage
- Vault storage where the company owes you a quantity of metal but doesn't necessarily own specific bars for you. You're an unsecured creditor. Read more →
V
- VAT (UK)
- 20% standard rate on silver, platinum and palladium bullion. Investment gold (≥995 fine) is exempt. Read more →
- Veriscan
- PAMP Suisse's anti-counterfeit system — encrypted barcode on each assay card that links to PAMP's verification app.
X
- XAU / XAG / XPT / XPD
- ISO 4217 currency codes for gold, silver, platinum and palladium respectively. Used by trading systems and price tickers.