Fineness
Also: Purity, Degree of Purity, Fine Gold Content, Karat
Fineness indicates how much pure precious metal is contained in an alloy — expressed in thousandths (e.g. 999) or in karats (e.g. 585 = 14 karat).
Fineness — also referred to as purity — describes the proportion of pure precious metal in an alloy. Pure precious metals are too soft for many purposes, so they are mixed with other metals (such as copper, silver, or palladium). Fineness indicates how high the proportion of the actual precious metal is in this mixture.
Two Notations: Thousandths and Karats
There are two common ways to express fineness:
- Parts per thousand (millesimal fineness): 999 means that 999 out of 1,000 parts are fine gold — i.e. 99.9%. This notation appears today on almost all bars and bullion coins.
- Karat (for gold): Here, 24 karat = 100% fine gold. 18 karat corresponds to 18/24 = 750/1000.
The most important gold alloys at a glance:
| Karat | Fineness | Fine Gold Content |
|---|---|---|
| 24 kt | 999 | 99.9% |
| 22 kt | 916 | 91.6% |
| 18 kt | 750 | 75.0% |
| 14 kt | 585 | 58.5% |
| 8 kt | 333 | 33.3% |
Why Fineness Determines Value
The material value of a piece of jewellery depends directly on its fineness. A 585 gold ring contains only 58.5% fine gold — the rest is copper and silver, which contribute little to the precious metal value. To calculate the pure metal value (the melt value), you multiply the weight by the fineness and the current gold price. This is exactly what the melt value calculator does automatically — including for mixed lots of 333, 585, and 750 gold.
Hallmarks (Fineness Stamps)
In Germany, precious metal items may be stamped with a hallmark indicating the fineness — for example "750" for 18-karat gold or "925" for sterling silver. Unlike many neighbouring countries, Germany does not have a statutory obligation to stamp items, but any stated fineness must be accurate. Dental gold usually lacks a hallmark altogether; the specialised dental gold calculator is helpful here, as it works from typical alloys between 750 and 900.
In Brief
Fineness is the key to material value: without it, no reliable value can be derived from weight and the current price. Anyone wishing to value jewellery or scrap gold should always determine the fineness first — via the hallmark or an expert assessment.