How pure is your gold?

Pure gold, the rich, unpolished opulence that you’ll see in museums is not generally used for jewellery these days in the West.


Pure gold is incorruptible, I love that phrase, it means that gold is inert and it won’t tarnish in contact with oxygen.


Have you ever noticed how some old, richly gold coloured rings have worn away underneath? It’s because they were made using a high proportion of gold, 90% or more mixed with up to 10% of other pure metals. Pure gold is comparatively soft for a metal and in rings worn daily, it will eventually become thinner.


This is why gold alloys (combinations of pure metals) are made. Pure, yellow gold is commonly alloyed with copper, silver, zinc and palladium to improve durability and to change its colour.

24ct pure gold grains, pure copper and pure silver.

Let’s talk gold carats (ct) in the UK or karats (k) in Canada and North America. Pure gold is 24ct/24k.

A carat is an old weight, equal to a scruple, or the twenty-fourth part of an ounce troy. The origin of scruple is the latin scrūpŭlus, denoting, a small sharp or pointed stone. Okay, back to carats…

A carat is 1/24 part, or 4.1667% of the whole metal, of pure gold. So a 22 carat gold pendant is made up 22 parts of pure gold and 2 parts of another pure metal (forming an alloy with 91.6% pure gold). Carats are expressed as the number of these parts of pure gold.

The carat number refers to the amount of pure gold. In the UK, for over 700 years, gold alloys have been Hallmarked by The Goldsmiths’ Company Assay Offices (the oldest form of consumer protection), and are now stamped as numbers that denote how many parts of pure gold there are in 1000 parts total.


Have a look at your jewellery, (you’ll need a magnifying glass). See if you can find the markings that tell you the metal fineness.


999 = 99.9% gold = 24ct/24k


900 = 90.0% gold = 22ct/22k


750 = 75.0% gold = 18ct/18k


580 = 58.0% gold = 14ct/14k


375 = 37.5% gold = 9ct/9k


Generally, the higher the percentage of pure gold the more “golden” the color of yellow gold and the softer the metal.

Clockwise from top: 24ct pure gold grains, 22ct yellow gold, 18ct yellow gold.

The rings and bangles I make for you are mainly 18ct gold. I find that it’s a good mix of colour and durability. The yellow colour is lighter and fresher compared with pure gold.

Stone-hammered solid 18ct yellow gold bangles


Sometimes I’ll use 22ct yellow gold for earrings or for the setting around a stone, it all depends on the colour that best suits the design.

Tender Box Ear Studs, 22ct yellow gold


Different gold colours are made by varying the pure metals used in the alloy. So, all 18ct golds will have the same amount of pure gold (75%), it’s the choice of pure metals for the alloy that changes the colour of the gold.


As you already know, 18ct yellow gold is alloyed with pure copper and pure silver and it has a lemony tone.


18ct red, rose, pink (or sometimes called Russian) gold is mainly alloyed with pure copper and a small amount of pure silver. It has a warm rosy tone.


White gold is alloyed with palladium, one of the platinum group metals and this gives it a wonderful deep gun-metal grey colour that I think of as ‘quietly serious.’


Then there is the less well-known green gold, alloyed with pure silver. This has a slightly paler colour than 18ct yellow gold, more lime toned than lemon. You have to bear in mind that it is relatively soft, so it’s a good choice in a ring stack of contrasting gold colours, or used in settings for stones where a paler colour works best.

From L: 18ct green, white, rose and yellow gold rings

I like to use these different colours of 18ct gold in ring stacks where you can arrange them at whim to contrast while complimenting each other.


The stone-hammered texture that I impart to the metal reveals the richness of the gold, allowing it to show how distinctive the colour is, rather than reflecting the world around it as shiny metal does. Instead, I choose to hand-burnish or push just the corner edges smooth so that they glint as they catch the light.


Green gold is also another name for electrum, a naturally occurring alloy of gold and silver with trace amounts of copper and other metals. The natural colour of electrum ranges from pale to bright yellow, depending on the proportions of gold and silver. In Western Anatolia the gold content of naturally occurring electrum ranges from 70 - 90%.


I think it’s a lovely sounding word, electrum. The ancient Greeks called it “green gold” or "white gold.” The first metal coins ever made were of electrum and date back to the end of the seventh century or the beginning of the sixth century BC. In the Old Kingdom of Egypt, as early as the third millennium BC, electrum was occasionally used as an outer casing on pyramidions, the ornate caps that sat on top of ancient pyramids and obelisks.

That’s it, I could go on, but I’ll stop here.


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