The metal in a piece of jewelry decides its color, its weight, how well it holds stones and how it reacts with skin. Most fine jewelry uses gold, platinum, palladium or silver, each mixed with other metals for strength. Fashion and men's jewelry also uses titanium, stainless steel and bronze. This section covers each metal, plus the marks that tell you what a piece is made of.
The precious metals
Gold, silver, platinum and palladium belong to the noble metals, a group that resists corrosion in air and water. That stability is why gold objects come out of ancient tombs still bright.
- Yellow gold is gold alloyed with silver and copper. Its karat number tells you how much gold it contains.
- White gold mixes gold with nickel or palladium and is usually plated for a brighter white surface.
- Rose gold gets its pink to red color from extra copper.
- Platinum is dense, naturally white and usually sold at 95 percent purity.
- Palladium is a lighter metal from the same family as platinum, with a similar white color.
- Silver is the most affordable precious metal, used mostly as sterling (92.5 percent silver).
- Electrum is a natural gold-silver alloy used for the first coins and in ancient Egypt.
Rhodium plating belongs here too. Jewelers rarely use rhodium as a solid metal, but a thin coat of it gives white gold and much silver jewelry their bright finish.
Purity: karat and fineness
Pure gold, silver and platinum are too soft for most jewelry, so jewelers mix them with other metals. Gold purity is measured in karats out of 24, so 18K gold is 18 parts gold in 24, or 75 percent. Fineness gives the same information in parts per thousand: 18K gold is 750, 14K is 585, sterling silver is 925 and most platinum jewelry is 950.
Many countries stamp these numbers on jewelry. In the United Kingdom, independent assay offices test and hallmark precious metal items above set weights. In the United States, the maker applies quality marks under federal rules, without government testing. The precious metal hallmarks page explains how to read both systems.
| Metal | Common jewelry standards | Fineness marks |
|---|---|---|
| Gold | 9K, 10K, 14K, 18K, 22K | 375, 417, 585, 750, 916 |
| Silver | Sterling, Britannia, fine | 925, 958, 999 |
| Platinum | Platinum 950, 900 | 950, 900 |
| Palladium | Palladium 950, 500 | 950, 500 |
Hardness and wear
Purity and hardness pull in opposite directions. Pure 24K gold scratches and bends easily, while 14K gold, with more alloy metal, holds its shape better in a ring worn every day. Platinum scratches too, but a scratch mostly pushes metal aside, and the surface dulls to a soft gray patina over time. Silver scratches and dents more easily than gold.
Alternative metals behave differently. Titanium is light and strong. Stainless steel is hard and resists corrosion at low cost. Bronze, the copper-tin alloy that gave the Bronze Age its name, turns up in casual and artisan jewelry. Titanium and steel rings are hard to resize, so getting the size right at purchase matters more.
Allergies and skin reactions
Nickel is one of the most common causes of allergic contact dermatitis. It appears in some white gold alloys, in much cheap plated jewelry and in most stainless steels. People who react to nickel often do well with platinum, palladium, palladium white gold, high-karat yellow gold or titanium. Copper-rich alloys such as bronze and low-karat gold can leave a harmless green or dark mark on skin where sweat reacts with the metal.
The metal also affects which gemstone settings work and how a piece should be cleaned. The metallurgy glossary defines the trade terms used across this section.
Frequently asked questions
Which jewelry metal is the most durable for rings?
Platinum and 14K gold both hold up well in daily wear. Platinum keeps its metal when scratched, and 14K gold resists dents better than 18K or 22K gold.
What does 750 mean on jewelry?
It means the metal is 750 parts per thousand gold, which is 18K or 75 percent gold. The same system marks sterling silver as 925 and most platinum as 950.
Which metals are best for sensitive skin?
Platinum, palladium, titanium and high-karat yellow gold rarely cause reactions. Nickel white gold and some steels are the usual problem metals for people with a nickel allergy.