Green Gold
Also: Electrum, Green-tinted gold
Green gold is a gold alloy with a high silver content that gives the metal a characteristic greenish-yellow hue.
Green gold is created by alloying gold with a high proportion of silver - occasionally supplemented by small amounts of copper or cadmium. The combination of these metals absorbs certain wavelengths of visible light more strongly than pure yellow gold, producing the characteristic greenish shimmer. The current gold price forms the valuation basis for the fine gold content it contains.
Composition and colouration
The colour depends directly on the silver content: from about 15% silver the yellow tone begins to fade and shifts towards green. Common compositions for 18-carat green gold (750 gold) provide for around 20-30% silver; the rest is pure gold. Historically the term electrum was used for naturally occurring gold-silver alloys with 15-45% silver - the first coins of antiquity, for example in Lydia (7th century BC), were made of it.
| Silver content | Colour effect |
|---|---|
| 5-10 % | Slightly paler yellow gold |
| 15-25 % | Distinctly greenish-yellow |
| 25-35 % | Pale green |
| > 40 % | Light grey-green (rare in jewellery) |
Cadmium as an additive intensifies the green tone considerably but, owing to its toxicity, is largely banned in modern jewellery production.
Use in jewellery manufacture
Green gold is found above all in high jewellery and designer jewellery, where it is used as a contrast to red, white or yellow gold. Technically it is easy to work - similar to yellow gold - and can be soldered, drawn and stamped. The high silver content makes the alloy somewhat softer than red gold, which gains markedly in hardness from its copper content.
The melt value can be calculated quickly when weight and fineness are known; on purchase only the fine gold content it contains is likewise remunerated.
Distinction from other gold colours
- Yellow gold - classic gold-silver-copper alloy, warmer in tone
- White gold - palladium or nickel alloy, cool silvery
- Red gold / rose gold - high copper content, warm red tone
- Green gold - dominant silver content, cool yellow-green tone
In brief
Green gold is not a peculiarity of modern jewellery designers but one of the oldest gold alloys in human history. Anyone wishing to value a piece of green gold should check the fineness hallmark and refer to the current gold price - the silver content raises the weight, but not the gold value of the piece.