WHAT IS GOLD?
Pure gold is soft & is usually mixed with other metals to increase its strength; metals such as silver, copper, platinum & palladium. This “gold alloy” is used to make jewellery, coins, decorative items, dental fillings & much more.
What is a Carat?
The amount of gold in the “alloy” is measured as a unit or “carat”.
One carat (ct) is equal to one part in twenty four. Therefore, an 18ct gold ring contains eighteen parts of pure gold & six parts of an alloy material.
9 carat = 9/24 9 parts gold, 15 parts alloy, 9ct is the hardest & cheapest
10 carat = 10/24 10 parts gold, 14 parts alloy
14 carat = 14/24 14 parts gold, 10 parts alloy
15 carat = 15/24 15 parts gold, 9 parts alloy
18 carat = 18/24 18 parts gold, 6 parts alloy & mostly used for Rose Gold
22 carat = 22/24 22 parts gold, usually 2 parts silver
24 carat = 24/24 Pure Gold, softest & most expensive
Because of the percentage make-up, this is why you will see “numbers” stamped on jewellery. For example:
9 carat = 37.5% of gold or “375” - Mainly used by Britain & the Commonwealth countries, not recognised by the US.
10 carat = 41.6% of gold or “416” - This is the minimum gold standard of the US.
14 carat = 58.3% of gold or “583” - Mainly used by the Asian market, though also used in the US & Russia. NB. US market uses “585”
15 carat = 62.5% of gold or “625” – Was used by British Commonwealth countries & discontinued around 1935, a good indicator of the age of a piece of jewellery.
18 carat = 75% of gold or “750” - This is the minimum gold standard of Italy.
22 carat = 91.6% of gold or “916” - This is mainly used by the Asian & Middle Eastern markets.
24 carat = 100% of gold & ONLY seen in gold bullion bars.
Colours of Gold
Yellow Gold – Is probably the most common of gold colours, it consists of gold, silver, copper & zinc, with different percentages of all, for each of the carats of gold. For example: 9ct gold is 37.5% gold, 11.5% silver, 40.8% copper & 10.2% zinc.
Rose Gold - Almost all of the rose gold produced is composed of 75% gold & 25% copper. Therefore, it is mainly 18ct gold “750” that will be rose gold. It is sometimes known as “Russian Gold” as it was popular in Tsarist Russia before the revolution.
Pink Gold - Again, the same as rose gold, almost all of the pink gold produced is composed of 75% gold, 21% copper & 4% silver & again because of this percentage make-up, it is an 18ct gold.
White Gold - This alloy is commonly available in 10ct, 14ct & 18ct. The metals mainly used along with gold for 10ct & 14ct are silver, palladium & zinc. Nickel was used, but this has now been banned in many European countries because people had allergic reactions to it & it has carcinogenic properties. 10ct white gold is made up of 41.6% gold, 47.4% silver, 10% palladium & 1% zinc. 14ct white gold is made up of 58.3% gold, 32.2% silver & 9.5% palladium. 18ct white gold is 75% gold & 25% platinum or palladium.
Red Gold – Not heard of very much these days, it was normally used for 18ct gold jewellery & its makeup was 75% gold & 25% copper.
Purple Gold – A relatively new colour of gold, making its debut in 2000 with the patent established in 2002, currently only used by the Asian market. Unfortunately, purple gold is a lot more brittle than other gold alloys, this is a fault when formed in the electrolysis & a sharp blow or dropping it, may cause it to shatter. This 20ct gold is made up of 80% gold & 20% aluminium.
What is the difference between White Gold & Platinum ?
Both metals have totally different compositions, which make them unique. White gold is an alloy of yellow gold & some white metal (as explained above), with the natural hue of white gold being slightly grey in colour. Platinum is a white metal that is approximately 95% pure. It is very white, extremely hard & long lasting. It is much more expensive than white gold, for example a platinum ring will cost twice the price of an 18ct white gold ring.
What is Gold Plated ?
This is NOT gold jewellery. It is a base metal, which has had a microscopic layer of gold alloy electroplated over the top. The gold alloy will rub off; use a pencil eraser to the inside to test.