Red Gold
Also: Copper gold
Red gold is a gold alloy with a high copper content that gives the metal its distinctive reddish to warm bronze-coloured tone.
Red gold is produced when copper, and depending on the recipe small amounts of silver, is deliberately blended into pure gold. The raised copper content overlays the warm yellow tone of gold and creates shades ranging from a delicate rosé to a rich, almost copper-coloured red. The higher the copper content, the more intense the red colouring. Knowing both the gold price and the copper price is therefore essential when calculating the melt value of red gold jewellery, since both feed into the melt value calculator.
Composition and fineness levels
The precise colour depends on the ratio of the alloying metals. The following combinations are common:
| Fineness | Gold content | Copper content | Silver content | Colour effect |
|---|---|---|---|---|
| 333 (8 carat) | 33.3% | up to 60% | remainder | Strongly reddish-coppery |
| 585 (14 carat) | 58.5% | 35-41% | 0-6% | Rich red-gold |
| 750 (18 carat) | 75.0% | 25% | 0% | Warm reddish-gold |
If the alloy contains no silver, it is classic red gold with maximum red colouring. When silver is added, the tone shifts towards rose gold, which is distinguished from the stronger red gold by its pastel-pink hue. These transitions are fluid; the terms red gold and rose gold are sometimes used interchangeably in the trade, even though strictly speaking they denote different copper contents.
Calculating the melt value
The material value of red gold jewellery arises from the fine weight of the gold (and, proportionately, the copper, which is usually ignored in valuation because its contribution is small). The formula is:
Melt value = gross weight (g) x fineness (per mille) / 1000 x gold price (EUR/g)
A 10-gram ring in 585 red gold therefore contains 5.85 g of fine gold. The current price per gram is determined by the gold calculator.
Properties and working characteristics
Copper makes gold alloys considerably harder and more wear-resistant than pure fine gold (999). Red gold with 585 fineness solders, stamps and engraves well. The greater hardness is an advantage in jewellery: rings and bracelets withstand the mechanical stresses of everyday life better than those made of yellow gold.
The high copper content does, however, bring drawbacks:
- Tarnishing: copper oxidises in moist air, so red gold jewellery may tarnish slightly over the long term, though this can be remedied with common jewellery care products.
- Allergy risk: copper-bearing alloys can trigger skin irritation in sensitive people, which is why 750 red gold (less copper) is better suited to sensitive skin.
- No protective layer: unlike rhodium-plated white gold, red gold offers no additional protective coating.
Distinguishing related alloys
| Term | Main alloying metal | Typical tone |
|---|---|---|
| Rose gold | Copper + silver | Pastel pink |
| Red gold | Copper (higher than rosé) | Warm red-coppery |
| Yellow gold | Balanced silver + copper | Golden yellow |
| White gold | Palladium or nickel | Silvery-white |
Market and buying
When selling or buying, only the fineness, that is the gold content, counts as the value-determining figure. Copper and silver are not remunerated separately in a typical precious metal purchase. The purchase price calculator helps to estimate the realistic proceeds for red gold jewellery in advance. Note: in Ireland, a gain on the sale of gold may be liable to Capital Gains Tax at 33% above the annual personal exemption of EUR 1,270, with no holding-period relief. This is not tax advice.
In a nutshell
Red gold owes its warm, reddish colour to the deliberately raised copper content in the gold alloy. Depending on the fineness (333 to 750), colour, hardness and melt value all vary; the melt value can be conveniently worked out with the melt value calculator.