GOLD INFORMATION

OVERVIEW
RELATIVE HARDNESS CHART

 

 

GoldGoldGold

 

OVERVIEW

Pure Yellow Gold (fine gold) is softer than pure silver, but harder than tin. Its beauty and lustre are unmatched by any alloyed gold (pure gold mixed with other metals). The extreme malleability, ductility, and softness of pure gold make it practically useless for jewellery applications. It is just too soft!

The addition of alloying elements (other metals) to gold are used to increase the toughness and hardness of the metal. While almost any metal can be alloyed (melted) with gold, only certain metals will not dramatically change the colour or make the metal brittle. The addition of the metal like Indium (great as an alloy with Platinum), for instance, turns gold into a purple color and gives resulting gold the workability of glass. Any pressure and it shatters.

Over time, certain percentages of gold have become legally recognized “carats.”

The carat indicates the amount of gold as a percentage of the total:

  • 24 carat is 24/24’s gold or 100% gold.
  • 18 carat is 18/24’s gold or 75% gold (25% of the other metals are non-gold)
  • 14 carat is 14/24’s gold or 58.33% gold. (41.67% of the other metals are non-gold)
  • 9 carat is 9/24’s gold or 37.5% gold. (62.5% of the other metals are non-gold)

In carat rated gold, there is a balance of the other metals in the non-gold percentage. These metals provide the various colors and hardness of carat rated golds.

Typical alloying metals mixed with gold and their colour visual effects are:

  • 24 carat Gold has a stunning visual Gold effect of course
  • Mixing Gold with Copper causes a visual Reddening effect
  • Mixing Gold with Silver causes a visual Greening effect
  • Mixing Gold with Zinc causes a visual Bleaching effect of the gold
  • Mixing Gold with Nickel causes a visual Whitening effect
  • Mixing Gold with Palladium causes a visual Whitening effect

How do jewellers use the above metal alloys to obtain different visual Gold colours?

  • 18k, 14k and 9k YELLOW GOLD is Gold alloyed with copper, silver, zinc
  • 18k, 14k and 9k WHITE GOLD is Gold alloyed with copper, nickel, zinc. WHITE GOLD IS NOT PLATINUM and vice-versa - see Platinum Information page.
  • RED GOLD (or ROSE) is Gold alloyed with just copper
  • GREEN GOLD (you hardly see it ever used) is Gold alloyed with just silver

Adjusting the proportions of colouring metal agents shown above provides the array of colours on the market.

So finally, what is the difference between 18k, 14k and 9k Yellow Gold and 18k, 14k and 9k White Gold?

Yellow Gold is alloyed with silver, while White Gold is alloyed with nickel. It is that simple.

So if someone ever tells you 14k White Gold and 14k Yellow Gold are different, they are correct to a point. They are different only in visual colour and whether one of the additional metals alloyed with the Gold was silver or nickel. They are not different as to their 58.3% pure Gold content and they are not different as to their percentages of alloyed copper and zinc.

Short answer is:

Are Yellow Gold and White Gold different metals? NO!

Are Yellow Gold and White Gold different Gold alloys? YES!

Even though it is called ‘White Gold’, the alloyed metal has a slight yellowish tint. A jewellery item made of White Gold is often electroplated with a thin coating of Rhodium, which is a member of the Platinum family metals (to make it more white from its yellow).

There really is no distinct advantage in using White Gold versus Yellow Gold; it is a matter of personal ‘metal’ visual preference.

Back to Top

RELATIVE HARDNESS - MOHS SCALE

10 Diamond

9 Corundum (Ruby, Sapphire)

8 Topaz

7.5 Beryl (Emerald, Aquamarine)

6.5-7.5 Garnet

7 Quartz (Amethyst, Citrine, Agate)

6.5 Steel File

6 Feldspar (Spectrolite)

5.5-6.5 Most Glass

5 Apatite

4 - 4.5 Platinum-Pure

4 Fluorite

3 Calcite (Also a penny!)

2.5 Gold-Pure(24Carat), Silver-Pure,(Fingernail)

2 Gypsum

1 Talc

- Back to Top - HOME -