750 Gold (18 Karat)
Also: 18 Karat Gold, 18k, 750, Au750
750 Gold refers to a gold alloy with a fineness of 750 parts per thousand (75.0%), corresponding to 18 karat, and is the most widely used quality in the jewellery and watch industry.
750 Gold — colloquially "18 karat gold" — is the world's dominant quality grade for high-quality gold jewellery and luxury watches. With a gold content of exactly 75 percent, the alloy offers a compelling compromise: it remains rich enough to preserve the characteristically warm gold colour and high material value, while being significantly more robust than near-pure fine gold (999). The melt value calculator helps to determine the current material value of a 750 piece in seconds.
Fineness and the Karat System
The fineness indicates how many grams of pure gold are contained in 1,000 grams of an alloy. For 750 Gold there are 750 out of 1,000 parts — three quarters. This corresponds in the karat system to exactly 18 out of a possible 24 karat, since 1 karat is by definition one twenty-fourth of the total weight.
Fineness (‰) = (Karat / 24) × 1,000
750 ‰ = (18 / 24) × 1,000
The remaining 25 percent of the weight consists of one or more alloying metals. Their composition alone determines the colour, hardness and further properties of the finished jewellery piece.
Alloy Variants and Colours
Depending on the ratio of the additive metals, optically very different gold qualities arise — all bearing the same 750 stamp:
| Colour | Gold Content | Main Additions |
|---|---|---|
| Yellow Gold | 75% | Silver (~12.5%), Copper (~12.5%) |
| White Gold | 75% | Palladium or Nickel, possibly Zinc |
| Red Gold | 75% | Copper (increased share, ~22%) |
| Rosé Gold | 75% | Copper (~20%), Silver (~5%) |
| Green Gold | 75% | Silver (increased share), no copper |
White gold with palladium addition is now the standard skin-compatible variant, because nickel white gold can trigger allergic reactions. Palladium white gold is frequently additionally rhodium-plated to brighten its slightly grey natural tone and make the surface more scratch-resistant.
Hallmarking and Identification
Every reputable 750 piece bears a hallmark that certifies the fineness. In Germany and the EU, the marking 750 (per-mille stamp) or 18K (karat stamp) is standard. British pieces show the hallmark stamp with the numeric code 750; older continental European pieces occasionally bear the signature Au 750. A missing or illegible stamp is not a reliable quality indicator — if in doubt, an X-ray fluorescence analysis provides clarity.
Calculating the Melt Value
The material value of a 750 piece can be derived from the current gold price and the weight of the piece:
Melt Value = Weight (g) × 0.750 × Gold Price (€/g)
Example: A ring weighs 6.0 g, the gold price is €85.00/g.
Melt Value = 6.0 × 0.750 × 85.00 = €382.50
The gold calculator performs this calculation automatically with the current daily price. When selling to a buyer, the price actually paid is usually slightly below the melt value, as melting and processing fees apply. The buying price calculator shows realistic comparison values.
750 Gold in Dental Technology
Historically, 750 Gold was also used in dental technology. Classic dental gold alloys for crowns, bridges and inlays frequently contain exactly this fineness, supplemented by platinum, palladium and silver for increased strength and biocompatibility. Anyone wishing to realise the value of old dental prostheses can use the dental gold calculator to determine the approximate material value.
Comparison with Other Finenesses
| Alloy | Fineness | Karat | Typical Use |
|---|---|---|---|
| 333 Gold | 333 ‰ | 8 kt | Entry segment, fashion jewellery |
| 375 Gold | 375 ‰ | 9 kt | UK jewellery market |
| 585 Gold | 585 ‰ | 14 kt | Mid-range jewellery, USA |
| 750 Gold | 750 ‰ | 18 kt | High-quality jewellery, watches |
| 916 Gold | 916 ‰ | 22 kt | Coins, Asian gold jewellery |
| Fine Gold | 999 ‰ | 24 kt | Bars, bullion coins |
750 Gold is clearly positioned in the premium segment. Compared with the widely used 585, the gold content is around 16.5 percentage points higher (75% versus 58.5%) — this makes a noticeable difference to the material value and explains the significant price gap between the jewellery segments.
Buying, Selling and Tax Notes
750 jewellery and watches with 750 gold cases are readily tradable on the secondary market because the fineness is internationally recognised and easily verifiable. When purchasing from a dealer, the price always includes a surcharge over the melt value for workmanship, design and trade margin. On resale, however, mainly the material value is reflected.
For private sellers in Germany: gains from the sale of jewellery and precious metals may fall under the speculative holding period (§ 23 EStG) if less than one year has elapsed between purchase and sale. After expiry of the one-year period, gains are generally tax-free, provided the tax-free allowance is not exceeded. Note: This is not tax or investment advice; for binding information please consult a tax adviser.
For cash purchases from €2,000 upwards, the Anti-Money Laundering Act (GwG) applies — identity verification by the dealer is mandatory.
In Brief
750 Gold (18 karat) combines a high fineness of 75% with good workability and everyday suitability — no wonder it is the preferred choice of goldsmiths and watch manufacturers worldwide. Anyone wishing to know the current material value of a piece is best served by the melt value calculator with the daily gold price.