Fine Gold Content
Also: Gold content, Gold fineness, Gold titre
The fine gold content states what proportion of a gold alloy consists of pure gold, expressed in thousandths (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 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
The fine gold content is expressed in two ways:
- Per mille: the international standard notation, also called the "thousandths hallmark". 999 means 99.9% gold, 585 means 58.5% gold. On bars and coins this number is often stamped in (fineness hallmark).
- Carat (ct): the traditional unit, mainly used in the jewellery trade. The scale runs from 1 to 24 carat, where 24 carat corresponds to pure gold (999.9).
The conversion between the two units is unambiguous:
Per mille = carat x (1000 / 24)
Carat = per mille x (24 / 1000)
Example: 18 carat x (1000 / 24) = 750
Common fine gold contents at a glance
| Carat | Hallmark | Fine gold content | Typical use |
|---|---|---|---|
| 24 ct | 999 / 999.9 | 99.9% / 99.99% | Investment bars, investment 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 the UK/Ireland |
| 8 ct | 333 | 33.3% | Lowest-grade gold jewellery |
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 - that is, the weight of the pure gold contained - is calculated as follows:
Fine weight = gross weight x (fine gold content / 1000)
Example: 10 g x (585 / 1000) = 5.85 g fine gold
Buyers and refineries always pay on the basis of the fine weight. A piece of jewellery in 750 gold with a total weight of 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 the EU VAT Directive, 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 bear the hallmark 999.9 (so-called "four nines"), which corresponds to the highest commercially usual degree of purity. Technically 999.99 (five nines) is possible, but scarcely widespread in the investment segment.
Testing the fine gold content
Various methods are available to determine the fine gold content:
- Hallmark check: read the punch marks and fineness hallmarks 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 - the standard among 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 piece: it links weight and gold price to the real material value. Anyone who knows the fineness can use the gold calculator to calculate the exact value of their gold at any time - whether jewellery, coin or bar.