Fine Gold Content
Also: Gold content, Gold fineness, Gold titre
Fine gold content indicates the proportion of a gold alloy that consists of pure gold, expressed in parts per thousand (per mille) or carats.
The fine gold content describes the percentage of pure gold in a gold alloy. It is the decisive figure when buying, selling and valuing gold coins, gold bars and gold jewellery – because not every "gold" contains the same amount of the valuable precious metal. The higher the fine gold content, the more valuable the piece is relative to its weight. The current gold price always refers to pure fine gold (999.9).
Units of measurement: per mille and carat
Fine gold content is expressed in two ways:
- Per mille (‰): the international standard notation, also called the "parts-per-thousand stamp". 999 means 99.9% gold, 585 means 58.5% gold. On bars and coins this figure is often stamped (fineness stamp).
- Carat (ct): the traditional unit, mainly used in the jewellery trade. The scale runs from 1 to 24 carat, with 24 carat corresponding to pure gold (999.9 ‰).
The conversion between the two units is unambiguous:
per mille = carat × (1000 ÷ 24)
carat = per mille × (24 ÷ 1000)
Example: 18 carat × (1000 ÷ 24) = 750 ‰
Common fine gold contents at a glance
| Carat | Stamp | Fine gold content | Typical use |
|---|---|---|---|
| 24 ct | 999 / 999.9 | 99.9% / 99.99% | Investment bars, bullion coins |
| 22 ct | 916 | 91.6% | Krugerrand, Sovereign (Crown Gold) |
| 21.6 ct | 900 | 90.0% | Vreneli, Napoleon (Latin Monetary Union) |
| 18 ct | 750 | 75.0% | High-quality jewellery |
| 14 ct | 585 | 58.5% | Everyday and fashion jewellery |
| 9 ct | 375 | 37.5% | Jewellery in UK/Ireland |
| 8 ct | 333 | 33.3% | Lowest-grade gold jewellery (continental) |
Fine gold content and material value
For valuation, the fine gold content is directly relevant: the melt value (also called material value) results from the gross weight of a piece multiplied by the fine gold content and the current gold price. With the melt value calculator this value can be determined in seconds.
The fine weight – i.e. the weight of the pure gold contained – is calculated as follows:
Fine weight = gross weight × (fine gold content ÷ 1000)
Example: 10 g × (585 ÷ 1000) = 5.85 g fine gold
Buyers and refineries always pay on the basis of the fine weight. A piece of jewellery of 750 gold weighing 20 g therefore contains 15 g of pure gold – the purchase price is calculated for this fine weight. The purchase price calculator shows the expected proceeds depending on fineness and weight.
Investment gold: special purity requirements
For VAT-exempt investment gold under UK law (HMRC; based on Directive 2006/112/EC) minimum requirements apply:
- Bars: at least 995 ‰ fine gold content
- Coins: at least 900 ‰ fine gold content, legal tender in the country of origin
Classic investment bars from manufacturers such as Heraeus, PAMP Suisse or Valcambi carry the stamp 999.9 (so-called "Four Nines"), which corresponds to the highest commercially common level of purity. Technically 999.99 (Five Nines) is possible, but rarely found in the investment segment.
Testing the fine gold content
Various methods are available for determining the fine gold content:
- Stamp check: read the hallmarks and fineness stamps on the piece (e.g. "750", "18K", "750/1000").
- Streak test: abrasion on the touchstone with acid – a quick dealer method, but imprecise.
- Acid test: reaction with nitric acid or aqua regia gives an indication of the content.
- X-ray fluorescence analysis (XRF): non-destructive, highly accurate measurement of the element content – standard for professional buyers.
- Density measurement (Archimedes): comparing weight in air and water allows conclusions about the alloy composition.
In brief
The fine gold content is the central figure of every gold item: it links weight and gold price to the real material value. Anyone who knows the fineness can use the gold calculator at any time to determine the exact value of their gold – whether jewellery, coin or bar.