750 Gold (18 Carat)
Also: 18 Carat Gold, 18k, 750, Au750
750 gold denotes a gold alloy with a fineness of 750 parts per thousand (75.0%), corresponding to 18 carats, and is the most-used quality in the jewellery and watch industry.
750 gold – colloquially "18 carat gold" – is the dominant quality grade worldwide for high-quality gold jewellery and luxury watches. With a gold content of exactly 75 per cent, the alloy offers a convincing compromise: it remains rich enough to preserve the characteristically warm gold colour and the high material value, while being considerably 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 Carat System
The fineness indicates how many grams of pure gold are contained in 1,000 grams of an alloy. For 750 gold, that is 750 of 1,000 parts – three quarters. In the carat system that corresponds exactly to 18 of 24 possible carats, since 1 carat is by definition one twenty-fourth of the total weight.
Fineness (‰) = (carat / 24) × 1000
750‰ = (18 / 24) × 1000
The remaining 25 per cent of the weight consists of one or more alloying metals. Only their composition decides the colour, hardness and other properties of the finished piece.
Alloy Variants and Colours
Depending on the ratio of the additive metals, visually very different gold qualities arise – all bearing the same 750 stamp:
| Colour | Gold content | Main additives |
|---|---|---|
| Yellow gold | 75% | Silver (~12.5%), copper (~12.5%) |
| White gold | 75% | Palladium or nickel, possibly zinc |
| Red gold | 75% | Copper (increased content, ~22%) |
| Rose gold | 75% | Copper (~20%), silver (~5%) |
| Green gold | 75% | Silver (increased content), no copper |
White gold with a palladium additive is regarded today as the skin-friendly standard variant, because nickel white gold can trigger allergic reactions. Palladium white gold is often additionally rhodium-plated to brighten the slightly greyish inherent tone and make the surface more scratch-resistant.
Hallmark and Marking
Every reputably made 750 piece carries a hallmark certifying the fineness. In the UK the mark 750 (parts-per-thousand stamp) or 18K (carat stamp) is usual. British pieces show the hallmark with the numeric code 750; older continental European pieces occasionally bear the signature Au 750. A missing or illegible mark is not a reliable sign of quality – when 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 £75.00/g.
Melt value = 6.0 × 0.750 × 75.00 = £337.50
The gold calculator carries out this calculation automatically with the current daily price. On sale to a buyer, the price actually paid is usually somewhat below the melt value, since melting and processing fees apply. The purchase price calculator shows realistic comparison figures.
750 Gold in Dentistry
Historically, 750 gold was also widespread in dentistry. Classic dental gold alloys for crowns, bridges and inlays often contain exactly this fineness, supplemented by platinum, palladium and silver for increased strength and biocompatibility. Anyone wishing to recycle old dental parts can use the dental gold calculator to estimate the approximate material value.
Comparison with Other Fineness Grades
| Alloy | Fineness | Carat | Typical use |
|---|---|---|---|
| 333 gold | 333‰ | 8 ct | Entry segment, fashion jewellery |
| 375 gold | 375‰ | 9 ct | UK jewellery market |
| 585 gold | 585‰ | 14 ct | Mid-range jewellery, USA |
| 750 gold | 750‰ | 18 ct | High-quality jewellery, watches |
| 916 gold | 916‰ | 22 ct | Investment coins, Asian jewellery |
| Fine gold | 999‰ | 24 ct | Bars, investment coins |
750 gold positions itself clearly in the premium segment. Compared with the widespread 585, the gold content is about 16.5 percentage points higher (75% versus 58.5%) – this is noticeably reflected in the material value and explains the marked price difference between the jewellery segments.
Purchase, Sale 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 buying from a dealer, the price includes, alongside the melt value, a surcharge for processing, design and trade margin. On resale, by contrast, it is mainly the material value that is reflected.
Under UK law, gains from the sale of jewellery and precious metals may be subject to Capital Gains Tax. The gain is calculated as disposal proceeds minus acquisition cost and is taxable above the annual exempt amount; there is no German-style one-year holding period. UK legal-tender coins from The Royal Mint are CGT-exempt, but jewellery is not. Note: This is not tax or investment advice; for binding information, consult a tax adviser.
On cash purchases, the UK Money Laundering Regulations require dealers to carry out identity verification as part of their anti-money-laundering obligations.
In Brief
750 gold (18 carat) combines a high fineness of 75% with good workability and everyday suitability – no wonder it is the preferred choice of goldsmiths and watchmakers worldwide. To find the current material value of a piece, it is best to use the melt value calculator with the daily gold price.