Different Types Of Gold
When people think of jewelry, they usually think of gold. For thousands of years, gold has been held as one of the most precious metals for people. Gold has been used in jewelry-making, for religious artefacts, coinage, in trading and commerce, and many other uses over the years.
But there are actually many different types of gold. What are the different types and different colors of gold that can be used?
Gold in its purest form is a chemical element with the symbol Au and atomic number 79. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable metal, which is what first attracted people to it.
Its low reactivity with other elements and to acids means that gold became perfect for day-to-day use in jewelry. However, pure gold is actually too malleable to be used by itself, so it is combined with other metal alloys to increase its strength.
These alloys can change the appearance of gold, making it appear a different color to its natural state, Gold jewelry is usually alloyed with silver, copper, zinc, palladium, and nickel to create different gold colors. The most common of these colors are yellow, white, rose, and green, but there are actually several more that are growing in popularity. Below is a table showing how the different alloys added to gold can affect the coloring.
The amount of an alloy mixed with a gold piece also affects the karat of gold jewelry. Karats are a fractional measure of purity for gold alloys, measured per 24 parts whole. i.e one karat is 1/24th of the mass, so 24-karat gold is pure gold. An 18-karat gold ring is 18/24 (or 3/4) gold and 1/4 other metal alloys.
Below is a list of the most common different colored golds found in jewelry
- Yellow gold – Usually when talking about gold jewelry, you are referring to yellow gold. Yellow gold is naturally occurring and is the purest form of the metal. For jewelry, it is made into an alloy by combining pure gold with metals such as silver, zinc and copper. Examples of the common alloys for 18K yellow gold include:18K yellow gold: 75% gold, 12.5% copper, 12.5% silver
18K yellow (darker) gold: 75% gold, 15% copper, 10% silver
- Rose gold – Rose gold, also known as pink gold or red gold, is a result of alloying pure gold with copper, as copper has a red tinge to it. The shade of rose gold can also vary greatly, depending on the proportion of copper blended with the gold. The greater the content of copper, the redder the final colour is. A common combination in jewelry for rose gold is 75% gold mixed with 25% copper.
A key point to keep in mind with white and rose gold is that since gold must be combined with other metals to transform the colour, it is impossible to achieve “pure” (or 100% / 24k) white or rose Gold.
Rose gold is more affordable than the other gold colors because it uses the inexpensive copper for its coloring. Due to its copper content, rose gold is also more durable than yellow or white gold.
- Green gold – Green gold, also known as Electrum, is mixed with gold, silver, and sometimes copper. Silver is what gives the gold alloy its greenish coloring. Green gold was known used by ancient people as long ago as 860 BC under the name electrum, a naturally occurring alloy of silver and gold. It actually appears as greenish-yellow rather than green.
The element Cadmium can also be added to gold alloys to create a green color, but there are health concerns regarding its use, as cadmium is highly toxic. The alloy of 75% gold, 15% silver, 6% copper, and 4% cadmium creates a dark-green alloy.
- Grey gold – Grey gold alloys are usually made from gold and palladium. A cheaper alternative which does not use palladium is made by adding silver, manganese, and copper to the gold in specific ratios.
- Black gold – Black gold is another type of gold used in jewelry. Black-colored gold can be produced by a couple of methods. Oxidation by applying sulfur-oxygen-based compounds is one way. Another is the controlled oxidation of gold containing chromium or cobalt (e.g. 75% gold, 25% cobalt. A range of colors from brown to black can be achieved on copper-rich alloys by treatment with potassium sulphide.
Cobalt-containing alloys, e.g. 75% gold with 25% cobalt, form a black oxide layer giving the gold a black coloring. Copper, iron and titanium can be also used for such an effect.
- Blue gold – Blue gold is an alloy of gold and either gallium or indium. A gold–indium alloy contains about 46% gold (about 11 karat) and 54% indium, forming an intermetallic compound with a rich blue color. With gallium, gold forms another intermetallic which has slighter bluish hue.
A rich blue colored gold of 20–23K can also be obtained by alloying with ruthenium and rhodium.
Which Type Of Gold Is The Most Popular?
Since it was first discovered in the earth in its natural state, the most common type of gold found throughout history is yellow gold. In ancient items, such as jewelry or religious artefacts, yellow gold is the most common due to its availability and the limited methods of alloying gold.
Since advances in science, however, and the knowledge to mix gold with other metals has grown, different gold colors have seen different periods of popularity. Of course, it can also depend on the fashion trends of the day.
The biggest choice that most people have to make when it comes to choosing a type of gold is color. Of course much of it is personal preference. Which color gold do you prefer? Which matches the best with your skin tone and fashion style?
Another factor to consider is the purpose of the gold. The properties of gold can vary largely, based on the metals and quantities used in the blend. The decision about the quantities of other metals with gold is based on their purpose and affects cost. For example, if gold is blended with a softer metal like palladium, it is ideal for gemstone settings in which a malleable gold alloy is needed.
The quantity in karat gold also affects the cost and durability. For example, a 10k gold ring vs a 14k gold ring. The 10k gold ring has been mixed with more alloys which makes it more durable for daily wear but has less gold content than a 10k ring. The 14k ring would have more gold which will be subject to daily wear more compared to 10k gold but has more value.
In terms of fashionable popularity, gold has also seen different periods. From the 1960s to 1980s, yellow gold was very popular. Then in the 1990s, the popularity of white gold started to take over. Recently, the popularity of rose gold has started to resurface in the past few years as well.