15 carat gold!? 10 carat? 12 carat? Rose/white/yellow gold - what does it all mean!!??

Gold can be very confusing. Here's a comprehensive guide to hold your hand as you navigate through all of the jargon! If you're an experienced buyer you'll know most of this but if you need to brush up, here goes...

 

 

What is gold?

Most metals you come across are  alloys - if you remember from chemistry at school, an element is something made up of one kind of atoms and an alloy is a metal that is a mix of different elements - so a 10p coin is an alloy of copper, nickel and steel. Gold is an element  - pure gold is made up of gold atoms and nothing else. However, In reality, nearly all gold traded and worn is not actually pure gold, it's an alloy of gold mixed with other stuff and this alloy can vary in what's called fineness (the measure of how much actual gold is in the alloy). The higher the percentage of gold, the higher the fineness. For some or other confusing reason, (look it up if you have time to kill!) the measure of fineness is not always given as a percentage but as carats, (sometimes shown as ct or k). And sometimes it's given as both. Then just to be more awkward, the scale that is used runs from 0-24 carats with 24 carat being 100% gold, 12 carat = 50% and so on. In the UK you're most likely to come across 9ct (37.5% or 375 parts per thousand) and 18ct (75% or 750 parts per thousand) gold or if you're looking at items bought in Europe, sometimes 14ct (usually marked 14k – so confusing!). Here's a table showing the types of gold you're likely to come across

 

Gold fineness	% gold	Fineness mark	Other possible marks	Notes
8 Carat	33.3	333	8k .333	Mostly German
9 Carat	37.5	375	9ct 9k .375	Common in UK
10 Carat	41.6	n/a	10k	Mostly USA
14 Carat	58.3	583	14k .583	Mostly Europe/ USA
15 Carat	62.5	625	15ct 15k .625	Mostly antique UK
18 Carat	75	750	18ct 18k .750	Widely used UK, Europe etc
22 Carat	91	916	22ct 22k 22 .916	Mostly antique UK or Asian gold
24 Carat	99.9	999	24k 24ct .999	Mostly bullion/bars etc

 

 

So 9 carat gold is 37.5% gold and 62.5% other metals meaning that its only just over a third gold so shouldn't really be described as gold at all! 

 

How about silver, platinum and other metals – are they measured in carats? 

Just to make things confusing, the fineness of other metals are measured slightly differently.

Silver is measured in parts per thousand but not in carats:

 

Silver type	% Silver	Fineness mark	Notes
Coin silver	50	Not usually	Usually old coins or objects made from melted coins
800 Silver	80	800 or no mark	Some antique items or from European countries
Sterling Silver	92.5	925 925s “Sterling” or will have full UK hallmark	Minimum standard in UK and most commonly seen. Also scandanavian. US Marked “sterling”
Britannia silver	95	950 or will have full UK hallmark	Rarely seen, often used on quality silver pieces
Pure silver	99.9 - 100	999	Bullion, silver bars etc

 

 

Platinum is marked in parts per thousand - 950 or 999 (or occasionally 900) so if you see this number on white metal, its probably platinum.

 

Palladium – You’re unlikely to come across palladium, if you do its usually pure and marked as 999 but some older pieces contain a slightly smaller amount of palladium

 

What is rose gold? 

Most gold is an alloy, a mix of metals. All metals are the same, silvery colour pretty much, apart from gold, which is, well, gold and copper, which is the familiar pink/orange colour. So rose gold is an alloy containing gold and a percentage of copper, the more copper, the more of a pink/rose colour you get. 9ct rose gold could be, say, 37.5% gold (giving a gold colour), 30% copper, adding a bit of pink into the mix and 32.5% silver. This is just an example, it wouldn't have to be exactly this mix but if it's 9 carat then it must contain 37.5% gold to legally be called 9ct gold. 

 

What's white gold!?

Up until the early 20th century jewellers had a limited choice of gold and silver to use when making jewellery. They used gold for the fancy stuff and silver for bigger chunkier, cheaper things. When setting diamonds they often used gold on the back (for swankiness) and silver to set the diamonds (to accentuate the sparkle). Then along came platinum, a harder to use but bright white, hard metal and this suddenly started to become fashionable. It's still the best metal to set precious stones with.

 

So the white metal look became popular but many customers who liked this look still wanted their items made of gold. So some clever person cooked up the recipe for "white gold". Gold is an alloy, a mix of metals and its colour is determined by the other metals in the mix. Pure gold is, guess what? Gold colour. To make it seem more of a white colour needs 2 things - one: it needs to be mixed with white, silvery metals, so 9ct white gold could be made up of 37.5% gold, 50% silver and 12.5% platinum.  Now if you're clever, you'll be saying, “hang on, if I had a ball of yellow plasticine, and 2 balls of white plasticine and I mixed them all up, I'd end up with a ball of light yellow plasticine!?” And you'd be right. And if you think of say 18ct white gold, which is 75% gold and 25% white metals, there's no way that that's going to look white! So what happens with white gold (which isn't white at all) is it needs to be plated with another white metal and this is usually rhodium. So, in summary, white gold is a mix of gold and white metals that makes a dull, light yellow/grey alloy and this metal is plated with a truly white metal (rhodium) to make it look white and like platinum. This is why white gold needs to be re-plated every now and then to maintain its sparkle. In our opinion - just go with platinum if you’re looking to buy, its now loads cheaper and its better suited to the job. 

 

Which is worth more, yellow, white or rose gold?

For the purpose of value, it doesn't matter if your gold is yellow, white, pink or green, it all comes down to how much actual gold is in the mix. And a gram of 9ct rose gold is worth the same as a gram of 9ct white or yellow gold and a gram of 18ct white gold is worth twice as much as a gram of any colour 9ct gold – easy!?  Feel free to throw fashion into the mix - rose gold had a bit of a thing a while back, before that it was white gold all the way and now yellow gold is making a comeback...but bear in mind a bullion dealer or jeweller probably doesn't care about fashion when buying it from you, they just want to know how much actual gold is in the mix.

 

10 carat gold? 12 carat? 15k? Are these real?

They’re not carat types used today in the UK but almost every number has been used or is used somewhere in the world. A high proportion of Victorian jewellery is 15 carat but may not be marked. Most American jewellery is 10 carat. A lot of Chinese, Indian and eastern gold can be 22/23/24 carat The list goes on. Bear in mind that not all countries hallmarking systems are as robust as others! In the UK you'd quite quickly end up in jail if you were marking 9 carat gold with an 18 carat stamp but with a lot of high carat gold elsewhere, the fineness mark can sometimes be taken as a suggestion only!  Interestingly, if you sent a piece of gold to the UK assay office to be hallmarked which you thought was 18 carat gold (75%) and it turned out to be 74.99999% gold, it would be stamped with a 9 carat (375) hallmark! This is because it is a zero tolerance system and the next currently available hallmark down in the UK is 9 carat. This also means that the fineness given is actually usually a little higher that the hallmark states (if you were to test with an X-Ray gun).    

 

Aren’t carats used to say how big a diamond is!?  

It is a really weird and confusing system! Diamonds and gemstones are measured in carats which is a measure of how heavy they are, 1 carat being 1/5 of a gram. But these type of carats have zero to do with the type used to measure gold fineness which is a measure of the amount of gold in an item by % (out of 24). Don’t blame us, we didn’t invent the system! 

 

We'll make a blog post on diamonds, carats, the 4C's etc soon - so that's something to look forward to! 

 

If in doubt about any of this or if you have items to sell or things that you'd like valued - get in touch!