Gold Has Many Forms

There are many different types of gold available from regular jewelry stores and online jewelery stores. Understanding the difference will help you make a better informed decision when purchasing your next piece of fine karat gold jewellery.

What does the term Karats refer to when describing Gold?

The first thing we need to cover about Gold is that the “K” in 9K or 10k gold stands for karats. Not to be confused with Carat (Ct), which is the unit of weight measurement for gemstones.

Karats is a measurement of the content of gold. Online Jewellery stores & regular jewelry stores rarely sell gold karats jewellery made from pure gold as gold is considered a soft metal and is too soft for everyday use.

Mixing the gold with other metals hardens it and makes it more durable and less likely to bend. The result is “karat gold”. Pure fine gold jewellery would also be too expensive for the average consumer.

So “karat” is the content of gold used in a gold alloy in jewellery. i.e :

9k gold contains 37.5% pure gold (375 parts per thousand parts).
10k gold contains 41.7% pure gold (417 part per thousand parts)(include 10k)
14k gold contains 58.5% pure gold (585 parts per thousand parts).
18k gold contains 75% pure gold (750 parts per thousand parts).

The most common karat gold used in Australia is 9k and 18k. 18k is more expensive than 9k as it has a higher gold content. Both these types can be found at online fine jewellery stores and bricks and mortar fine jewellery stores. In the USA, 10k & 14k gold are most popular.

Gold Stamps (hallmarks)

Karat gold is normally stamped (hallmarked) to indicate the type. E.g. 9k gold would either be stamped 9k or 375, 18k gold would be stamped either 18k or 750. The stamp doesn’t indicate the colour of the gold, it only refers to the gold content.

Most countries have laws requiring gold alloys be stamped with one of the standard hallmarks. This said, a halkmark doesn’t mean the item is what is says it is.

Hallmarks should not be confused with a manufacturing stamp which is unique to the manufacturer.

What is Fine Gold?

You will see offline and online the terms fine gold jewellery, fine gold & fine jewelry. What do these terms mean? They normally refer to karat gold. In other words, fine gold jewellery is jewellery that is not gold plated.

What is Solid Gold?

You will see the term solid gold mentioned at online jewelry stores and at regular fine jewellery stores. Gold is normally named solid gold when it is karat gold or fine gold. For example 9k, 10k, 14k, 18k and 22k gold is often said to be solid gold. Jewellery is not considered solid gold if it is gold plated.

What Makes Gold Different Colors?

The colour of the gold doesn’t make a difference to the gold content (karat rating). This is because the alloy has the same amount of gold in it. The gold is mixed with different metals to achieve different colours.

Yellow gold can vary in colour. 18k yellow gold will have a brighter yellow colour compared to 9k gold.

Rose gold is achieved normally by mixing pure gold with other metals such as cooper into it.

White gold is made by mixing pure gold with metals such as silver and palladium. It is often coated with a metal named “rhodium”. The rhodium gives jewellery a really white appearance. White gold jewellery normally needs to re-rhodium coated every 12-18 months. Your local jewelry store and even some online jewelry stores can easily do this for a reasonable price.

When comparing metals of the same karat, white gold tends to be a little more expensive.

Gold Plated Jewellery (also known as GEP or GP)

Gold plated jewellery describes jewellery that has a layer of gold applied to a base metal by an electrolytic process. This gives a look similar to karat gold. The gold plating will wear off after time. Gold plated jewellery is a cheap alternative. This type of jewellery is widely available and can be found at online jewellery stores, online accessory stores and offline stores.

Gold Filled Jewellery (also known as Gold Overlay)

Gold filled jewellery is a solid layer of gold bonded with heat and pressure to a base metal such as brass. Gold filled jewellery is a great cost effective alternative to solid gold jewellery. Unlike gold plated jewellery, good quality gold filled jewellery wears as well as solid karat gold and has the same look and lustre. For more about solid gold jewelry, see gold karat FAQ guide part 1.

The layer of gold in gold filled jewellery must be 1/20th of the total weight of the product. This layer is 50 to 100,000 times thicker that gold plated jewellery.

Gold Hardness

The difference in gold content also affects the gold’s hardness. 18k gold is slightly harder than 9k gold but this difference in hardness offers little practical advantage as they are virtually the same hardness. However, overall, 18k gold does tend to wear a little better over the years. Most online jewellery stores & regular fine jewellery stores would advise you to choose 18k gold for a wedding band as it wears a little better.