What is Gold?
Gold is the rarest metal in the world and has been considered a sign of wealth for years. A precious metal with distinctive bright yellow soft metal and in fine form is classified as 24 Karat.
The price of gold normally refers to pure elemental gold however this is not used to make jewellery as it would not hold shape and is not suitable for daily use.
What is the difference between 9ct and 18ct Gold?
In the UK all jewellery items above 1gm are required to have a British Hallmark stamped by the Government’s Assay Office to determine their authenticity.
Whether you’re buying yellow, white or rose gold the hallmark is still the same as it determines the percentage of gold used in the piece of jewellery.
The rest of the alloy metals used vary depending on what colour you’re looking to achieve. The karat refers to how fine the gold is with 24 Karat being pure or fine gold.
Carat usually refers to diamond or gemstone weight but either K or ct can be used for gold fineness.
There are many karats used for jewellery manufacturing however jewellery is not normally made from pure gold as it would be too soft and go out of shape easily. The higher the carat the softer the gold is.
The most commonly sold gold in the UK is 9ct and 18ct. This is indicated by carat and numerical value on a typical UK hallmark as well as the sponsors mark, traditional fineness symbol, Assay office mark and date letter mark to determine year of hallmark.
9ct has the 375 stamp (parts per 1000) which refers to 37.5% of gold mixed with other metals. 9ct is the hardest wearing gold however because of the low gold percentage is not recognised in the USA and Middle East.
18ct has the 750 stamp meaning it has 75% gold and is the gold used for most jewellery manufacturing as it has a high gold content but still hard wearing as it has 25% alloys to strengthen the gold.
Obviously the main reasons for mixing gold with other alloys is to make it stronger and to reduce the cost because pure gold is expensive. Whether you should buy 9ct or 18ct mostly depends on your budget as 9ct will cost less so will make a big difference if you’re buying a heavy piece of jewellery.
It also depends if you prefer the deeper stronger colour particularly if you’re buying yellow gold.
Is Yellow Gold more valuable than Rose or White Gold?
The gold content is the same in all colours of gold jewellery but to create different colour effect various alloys are used depending on the colour which you want the piece of jewellery to be.
To achieve white gold colour a white alloy will be usually made from palladium or platinum and added to pure gold. For 9ct white gold 37.5% would be pure gold mixed with 62.5% alloys, for 18ct white gold 75% would be fine gold and 25% would be the white alloy.
The finished product would still show hints of yellow especially when the item gets worn hence plating an additional layer of rhodium to enhance the white colour.
This does not reduce the value of jewellery as the gold percentage is still the same. Effectively white gold would be slightly higher in value than the other colours especially if Platinum is used in the alloy as that is also an expensive metal.
For Rose gold appearance Copper is used to give the pinkish red colour, making it tougher than yellow or white gold, the percentage of gold is still the same depending on gold fineness.
As copper is a cheaper metal for the alloy technically rose gold should be slightly cheaper however most jewellers would price the same jewellery with the same price as the difference is so small unless you’re buying a particularly heavy item then it’s a more significant difference.
Obviously 18ct Yellow Gold still has the same 75% pure gold with 25% different alloys hence making items from a variety of manufacturers appear slightly different in colour even if they are all classified as 18ct yellow gold.
Which colour gold you should buy depends on personal preference. The gold value is determined by karat or percentage of gold in the item regardless of the colour
What is Gold Plated?
Gold plating is applying a thin layer of gold onto the surface of another metal. Like gold there are different colours used for plating options.
There are various methods of plating which are used depending on material being plated.
Of course the main reason for gold plating is done over various metals to give the real gold colour at a fraction of the price. Gold plating is usually 1 micron (micrometre) and will last about a year depending on wear and care of the item.
Is all Gold Plated jewellery the same?
Gold plated jewellery includes silver and stainless steel amongst other metals used. Be wary when buying fashion jewellery as many cheaper base metals used can cause allergies especially if extra thin plating is applied for reduced cost. At Tresor Paris we use silver as base metal.
Some of our jewellery has Titanium or Stainless Steel both of which are considered Allergy Free suitable for all ages.
Sometimes gold plating is used on gold jewellery to enhance the colour, such as 18 karat plating applied onto 9 karat jewellery.
Also Rhodium plating is commonly used over white gold jewellery to increase shine and durability so the metal underneath becomes more resistant to scratching and tarnishing.
If you have an old item of white or platinum jewellery you’d be advised to polish and rhodium plate the item to restore its original shine.
Another type of plating which is often used on stainless steel is PVD coating which stands for Physical Vapour Deposition. This process gives a real gold colour and can be 10 times thicker than standard gold plating, making it last longer.
This process is more environmentally friendly whilst achieving striking colours, is nearly impossible to remove and won’t wear off on its own.
Vermeil is another type of plating and is used over silver. Available in gold or rose gold is a thick 18ct coating which is won’t tarnish but will fade as the item becomes dirty and worn.
How long should I expect my Gold Plated jewellery to last?
No jeweller will guarantee plated jewellery long term as that depends largely on how the item is worn. Even weather conditions where the item is being worn can affect the durability of the plating.
Taking care of Gold Plated jewellery
Taking care of all jewellery, whether solid gold or plated is an important part of your investment. Even with plated items looking after them in the right way will keep them shiny and looking new for much longer. It is advisable to take off any jewellery whilst showering or swimming and avoiding chemicals, lotions and perfumes over them. Extra care should be taken with diamond or crystal set jewellery as this could cause loss of stones as well as tarnishing. If you’re unsure always have your jewellery checked or serviced by a reputable jeweller for peace of mind.