Chemical element Au.
Atomic number 79.
Melting point 1,064 degrees C.
A bright yellow very malleable metal.
The Muruntau open cast pit in Uzbekistan’s Qizilqum desert is the largest producer with over 2 million ounces of gold per annum.
What does carat mean?
A measure of fineness (purity) of gold.
1/24 part of the whole and the purity of a gold alloy is expressed as the number of parts of gold it contains. So an object containing 18 parts gold and 6 parts alloy metal is 18ct gold.
Pure gold is 24 carat which is very soft and not practical for making jewellery so harder wearing alloys have been created.
18ct gold contains 75% pure gold.
14ct gold contains 58.5% pure gold
9ct gold contains 37.5% pure gold.
The other metals used to create the different alloys are silver, platinum, palladium, copper, zinc, cadmium and iridium.
What makes 18ct white gold?
75% pure 24ct yellow gold mixed with silver, palladium and iridium creates the alloy which is a very pale grey/yellow colour which is then rhodium plated after manufacture and polishing to create a very white surface.
What makes 18ct red gold?
75% pure 24ct yellow gold with 25% copper gives a lovely soft pink metal.