GOLD

What is Karat?

The term carat, when used with gold, is a quality mark and measures the fineness of gold. Pure gold is known as 24 carat gold. If gold jewellery is then taken as consisting of 24 parts, jewellery of 18 carat gold would mean that 18 parts are pure gold, and the remaining six parts are other metals. Americans use the letter "K" to represent "Karat"; while the Europeans use a scale based on a thousand parts. The following table explains this:

24 carat gold:

pure gold or at least considered to be 100 per cent. If we think of a gold item as something composed of 24 parts and all the parts are pure gold, the item is 24 carat.

 

22 carat gold:

91.6 per cent pure gold-if 22 parts are pure gold, two parts are of at least one other metal.

 

18 carat gold:

75 per cent pure gold-if 18 parts are pure gold, six parts are other metals.

 

14 carat gold:

58.5 per cent pure gold-if 14 parts are pure gold, 10 parts are other metals.

 

Fine Gold Percentage

Carat System

Carat Mark

European System

European Mark

100.0

24

24ct

1000 parts

999

91.6

22

22ct

916 parts

916

75.0

18

18ct

750 parts

750

58.5

14

14ct

585 parts

585

37.5

9

9ct

375 parts

375

What other metals are mixed with gold?

Although extremely beautiful, pure gold - 24 carat gold - is so soft that it would gradually wear away with everyday use. Gold used in jewellery is usually alloyed (mixed) with other metals to strengthen and harden it, as well as change its colour.

For example: 18 carat yellow gold is made up of 75 per cent gold, 12.5 per cent silver and 12.5 per cent copper.

If the colour of gold is:

The alloy combination is:

yellow

gold + silver + copper

rose

gold + copper

white

gold + nickel, palladium, platinum and zinc

green

gold + silver + zinc or cadmium

What is white gold?

White gold is an alternative to platinum (white gold uses a lower heat and same tools as yellow gold). When white gold is alloyed, it is not exactly white so rhodium plating has to be applied to give it a shiny, white finish. Rhodium is a silvery white metallic element of the platinum family, used to electroplate microscopes and instrument parts to prevent corrosion.

How do I care for gold jewellery?

Follow these simple rules:

  • Keep your gold jewellery separated so that one piece does not scratch another and chains do not tangle.

  • Keep your gold jewellery dry-because washing up or showering leaves a dull soapy film on it.

  • Keep your gold jewellery clean-use a commercial cleaner, or clean with soap and water and a soft bristle brush, rinse in lukewarm water and allow to dry completely. Dip gold jewellery in methylated spirits to remove grease, oil and make-up.