Gold

Gold is a is a precious metal with the chemical element symbol Au. It is a bright, slightly orange-yellow, dense, and soft metal. Gold is a relatively rare element that has been used for coins, jewelry, and works of art throughout history. Gold is the most malleable of all metals. It can be made into a single-atom width wire. Gold often occurs as nuggets, veins, and river deposits. Because pure (24k) gold is soft, it’s usually alloyed with other metals for use in jewelry making. It makes it harder and more durable. Alloys with lower karat ratings, such as, 22k, 18k, 14k, and 10k, contain higher percentages of copper, silver, palladium or other metals.

The gold proportion of alloys is measured by karat (k). Pure gold is designated as 24 karat (24/24 parts gold) and abbreviated 24k. There are different gold alloys used in jewelry with 18 karat (75% pure gold), 14 karat (58% pure gold), and 10 karat (41.7% pure gold) being common. In the United States and many other countries, 10K gold (10 parts gold and 14 parts other alloys) is the lowest level of purity that can be legally be marketed and sold using the word “gold.” Others seen are 9k (37.5% gold) and 22k (91.70% gold).

24 Karat Gold
24k gold is the purest and is 99.9% yellow gold. It is the shiniest, yellowest, and most expensive type of gold. Pure gold is hypoallergenic and safe to wear if you have sensitive skin. It also has a high resistance to tarnish and corrosion. 24 karat gold is soft and not ideal for jewelry because it wears out easily.

Common 24 Karat Gold Stamp Marks:
Gold (pure gold)
24 Karat or 24K (24/24 parts gold)
999 (999/1000 parts, or 99.9% gold)

18 Karat Gold
18k gold consists of 75% pure gold and 25% other metals such as silver, copper, and zinc. It is much stronger and more durable than 24k gold and is used in a wide variety of jewelry. 18k gold doesn’t have the same intense yellow color of pure gold. Nickel can cause skin irritation. If the 18k gold alloy contains nickel, it is so low as to be a concern for most people, even those with sensitive skin.

Common 18 Karat Gold Stamp Marks:
18 Karat or 18K (18/24 parts gold)
750 (meaning 750/1000 parts, or 75% gold)

14 Karat Gold
14k gold is the most popular type of gold karatage sold in the United States. It is made from 58.3% pure gold and 41.7% other metals. 14k gold isn’t as bright as 18k, but it’s stronger and less expensive. Allergic reactions to nickel in 14k gold are uncommon.

Common 14 Karat Gold Stamp Marks:
14 Karat or 14K (meaning 14/24 parts gold)
583 (meaning 583/1000 parts, or 58.3% gold)

10 Karat Gold
Containing 41.7% pure gold, 10k gold is the minimum that jewelry can legally be sold as gold in the United States. 10k gold is durable, but its low purity gives it a paler yellow color. For some, this makes it a less popular gold alloy for special types of jewelry, such as wedding rings. Nickel in 10k gold jewelry is more likely to cause problems for those with nickel allergies, since it often has a higher nickel content.

Common 10 Karat Gold Stamp Marks:
10 Karat or 10K (meaning 10/24 parts gold)
417 (meaning 417/1000 parts, or 41.7% gold)

9K is considered real gold in other parts of the world and is the lowest permitted gold purity sold in the UK and Europe. 9K is 9 parts pure gold and 15 parts other metals. In other parts of the world Karat may be spelled Carat.

White Gold

White gold is an alloy of yellow gold and white metals, and sometimes also copper. The less gold and copper content in the metal alloy, the more white it appears. White gold jewelry is usually plated with rhodium, which makes it even whiter. White gold is usually formed from one of two different alloys:

Palladium white gold is a mixture of gold, palladium, and sometimes silver. Palladium is a hypoallergenic precious metal that’s rarer than gold. Common alloy percentages:

18K White Gold: 75% Gold, 0-10% Silver, & 15-25% Palladium
14K White Gold: 58.3% Gold, 28-35% Silver, & 8-14% Palladium
10K White Gold: 41.7% Gold, 46-48% Silver, & 7-11% Palladium

Nickel white gold is not hypoallergenic. It consists of gold, nickel, copper, and zinc. This form of gold is more affordable than palladium white gold. Common alloy percentages:

18K White Gold: 75% Gold, 17-19% Nickel, 4-6% Zinc, & 2-3% Copper
14K White Gold: 58.3% Gold, 7-9% Nickel, 6-8% Zinc, & 18-20% Copper
10K White Gold: 41.7% Gold, 16-18% Nickel, 11-13% Zinc, & 29-31% Copper

Rose Gold

Rose gold first came into wider use in the late 1800s, after it was introduced to the Russian Imperial court by Carl Fabergé. Rose gold is made from gold, copper, and silver. Copper is what gives rose gold its pinkish color. Most rose gold alloys are either 18k or 14k. 18k rose gold is shinier but has a paler rose color. 14k contains more copper and is less bright, but has a deeper rose color. Common alloy percentages:

18K Rose Gold: 75% Gold, 22-23% Copper, & 2-3% Silver
14K Rose Gold: 58.3% Gold, 31-33% Copper, & 8-10% Silver
10K Rose Gold: 41.7% Gold, 37-39% Copper, & 19-21% Silver