Demystifying Common Jewellery Terms
Know your carats from your karats, and your sterling from your vermeil.
Do you know your karats from your carats, or even from your carrots (sorry, couldn’t resist)? Why is sterling silver the marker of quality and why is it called “sterling”? And, what’s the difference between gold vermeil, plate and filled and when should you be choosing each? We’re here to help demystify common jewellery terms so you can make an informed decision and select the best piece for you. So let’s dive in…
ALLOY
Let’s start with the base, the foundation of every piece of jewellery, the alloy. An alloy is simply a blend of two or more metals. Different metals have different properties so the particular mix can change the overall strength, colour or cost. The proportion of metals in the alloy is represented by common jewellery terms like sterling silver and gold carats. You only really need to take note of the alloy mix if you are allergic to any of the components.
The “fineness” is the proportion of silver or gold in the alloy, usually illustrated in parts per thousand. This is where the 925 stamp comes from for sterling silver; there is 925/1000 parts pure silver in that piece of jewellery.
Which brings us onto the next part nicely…
STERLING SILVER
Sterling silver is probably the most universally recognisable mark of quality in silver jewellery. It’s many people’s go-to when choosing their jewellery, but what does it actually mean?
Sterling silver is a type of alloy comprising 92.5% pure silver with the remaining 7.5% usually a base metal (i.e. not a precious metal) like copper or zinc. You can recognise sterling silver by looking for the 925 stamp.
That’s all well and good but why “sterling” silver. There is a bit of debate around this but a common theory is that it comes from the Old English word “steorling” or “coin with a star” as some Norman pennies depicted a star. The pennies were 925 parts silver per thousand leading to not only sterling silver to be called as such but the currency in the UK to be called pound sterling to this day.
Although sterling silver is probably the most commonly used silver alloy in jewellery, there are others around - Fine silver (999 fineness), Britannia (958 fineness) and on the other end of the spectrum coin silver (from 750 parts silver). At House Thirteen we use only 925 sterling silver for all our jewellery and don’t currently have any other alloys. Not only that, but we are moving to 100% recycled silver but that’s a story for another time…
GOLD
Now on to all that glitters, and is gold. First let’s get the karat vs carats out of the way:
Carat: A carat is a unit of weight for precious stones. One carat is equal to ⅕ of a gram.
Karat: A unit to measure the purity of gold. It’s measured in parts per 24, with 24 carats being pure. UK standards of gold are 9k, 14k, 22k and 24k, going up in purity as you reach 24k. The proportions of pure gold vs alloy for each karat are below, and the softness of the metal increases the purer it gets. The “sweet spot” for jewellery is usually 18 karats as this is a good balance between colour, quality and durability.
9k - 37.5% gold
14k - 58.5% gold and 41.5% alloy
18k - 75% gold and 25% alloy
24k - Over 99.95% pure gold
To complicate things slightly, “karat”/ “k” is actually the American spelling, whilst “carat” / “ct” is the English equivalent, so you might find them used interchangeably. The American version just helps to differentiate it from carat weights of gemstones.
We may a want a jewellery box full on solid gold good,ess, but, alas, that might be a little out of reach for some of us. So if your budget doesn’t quite stretch to solid gold, then gold-plate is your friend. It’s lighter in weight and lighter on the wallet. How the jewellery is plated and with what will affect how much it costs, how it wears over time and how long it will ultimately last without needing to be re-plated.
GOLD-PLATED
Gold-plated is exactly what it says on the tin; a thin layer of gold placed onto the surface of a different base metal (usually silver, brass or copper) using chemicals or electrolysis.
The thickness of this plating will determine how long the coating of gold will last for; this is measured in microns. Typically the higher the micron, the more wear it will endure. If you are planning to wear your piece daily, or it’s on a high traffic area like a ring then you will need to look out for higher microns. If it’s an occasional piece or it won’t be subjected to much wear and tear like an earring, then you can get away with less microns. As a guide, the standard number of microns is 0.5 and upwards, but for our 18k gold-plating we typically use 1 micron on our earrings and 2 microns on necklaces and bangles which is much higher, to ensure they last for years to come. There is no regulations when it comes to the thickness of gold-plate so if you want to know, do ask.
When to choose gold-plate - It’s lightweight and the cheapest option to get that glimmer, but it’s also the thinnest of the plating options so the colour may fade over time if not properly cared for. Gold-plated jewellery can always be re-plated so it’s not the end of the road for them if they fade.
GOLD VERMEIL (ver-may)
Originating from 19th century, gold vermeil (also known at “silver gilt” or “gilded”) is a higher-quality and more regulated form of gold-plating. It’s also pretty fancy to say. Where standard gold-plating is quite flexible in terms of base metal and thickness, gold vermeil must be a minimum of 2.5 microns of at least 10k gold, plated over a 925 sterling silver base. This makes it not only more luxurious in terms of quality of metals, but also around five times thicker than the average gold-plating. As a result, it should last longer when properly cared for.
We love gold vermeil for it’s luxury, wearability and style and are planning to add it to our next collection.
When to choose gold vermeil - The next step up in price, this is a great option if you’re looking for a longer lasting, thicker gold finish and want the quality of a sterling silver base, for a price that won’t break the bank (as much!).
GOLD FILLED
Gold filled, also known as “rolled gold” or “gold bonded”, is created by mechanically bonding a layer of gold onto the base metal, which can be copper or brass as well as silver. It’s then bonded to the surface using heat and pressure. It’s much thicker than gold-plating, 5-10 times thicker to be precise and must be at least 5% of the weight of the piece by law (compared to 0.05% when gold-plated). This means it won’t tarnish or fade over time like gold-plated pieces. It’s also less likely to trigger any allergy the wearer may have to the metal it’s bonded to which makes it similar to, but more affordable than, solid gold.
When to choose gold filled - This option is the most expensive but won’t tarnish or fade, and is hypoallergenic - qualities most similar to sold gold without the price tag.
That’s just the tip of the gilded iceberg when it comes to what lies beneath the jewellery and the myriad of terms to look out for. We have chosen to create our pieces using sterling silver and 18k gold-plate so far. Our plating is thicker than that standard ensuring your pieces last, but we are looking to develop a gold vermeil collection soon. Please feel free to reach out if you have any questions about any of our pieces or jewellery in general and we’d be happy to chat.