Something I'm asked a lot is: What's the difference between 9ct and 18ct Gold? All golds (apart from pure gold) are an alloy of gold and other metals. The number of Carats (ct) refers to the amount of pure gold that is present in the alloy and the higher the number, the more gold is present and the more expensive the metal.
The amount of gold present also alters the colour of the gold, this is most obvious in Yellow Gold. In the image above you can see clearly that the 18ct Yellow Gold ring on the left has a much stronger yellow colour than the more muted 9ct Yellow Gold on the right.
9ct Gold: contains 37.5% pure gold
14ct Gold: contains 58.5% pure gold
18ct Gold: contains 75% pure gold
22ct Gold: contains 91.6% pure gold
24ct Gold: contains 99.9% pure gold
Gold is an extremely soft, malleable metal and so the higher the Carat of gold the softer the metal is, the highest carats 22ct and 24ct are not considered suitable for stone set jewellery as the metal is too soft. For this reason gold is alloyed with other metals to give it different properties, strength and durability being the main consideration, these other metals also alter the colour of the alloy giving you different shades of gold, i.e Yellow, White and Rose Gold.
White Gold
Is usually alloyed with white metals such as palladium or silver to give it it's "white" colour, which is actually a very pale yellow. The yellow colour of White Gold increases depending on the amount of gold that is present: 9ct White Gold is the palest white and 18ct has a slightly darker colour.
White Gold looks great when paired with monochrome stones such as White or Salt and Pepper Diamonds, White Sapphire or Black and Grey Sapphires.
Rose Gold
Sometimes called Red or Pink Gold, Rose Gold is usually an alloy of gold, copper and silver and it is the copper content that gives the metal it's "pink" colour. For this alloy the lower the carat the stronger the colour as it contains more copper.
18ct Rose Gold will contain 75% Gold and may only have 25% copper giving it a less obvious pink tinge. Where as 9ct Rose Gold contains more copper giving the metal a stronger pink colour.
9ct Rose Gold looks great when paired with cool tones, in particular coloured Sapphires such as Blue, Teal or Pink. 18ct Rose Gold has a slightly warmer colour and looks amazing paired with warm tones like Champagne Diamonds or Rubies.
Yellow Gold
Yellow Gold tends to be a mix between Gold, Silver and Copper in different amounts to Rose Gold. In this case the higher gold content, the stronger the yellow colour of the metal.
18ct Yellow Gold has a strong, bright yellow colour, whereas 9ct Yellow Gold has a more muted, warmer yellow colour (see top image).
Yellow Gold works brilliantly with brightly coloured stones, such as Rubies and Sapphires as well as more traditional monochrome stones.
My advice when choosing a metal would be to go for the colour you prefer above all else, don't worry too much about the different alloys and combinations.
When choosing a metal colour, you might also want to consider whether your piece will be stone set or plain and what effect the colour of metal might have on the stone combinations.
If you have any questions about the different metals you can get in touch with me at: info@emmawylie.co.uk