What is the chemical symbol for gold?
Quick answer
The chemical symbol for gold is Au, from the Latin word aurum, meaning “shining dawn” or “glow of sunrise.” Gold’s atomic number is 79, which means each gold atom has 79 protons.
Key facts
- Symbol
- Au
- Atomic number
- 79
- Melting point
- 1,064°C (1,948°F)
- Density
- 19.3 g/cm³
Why “Au” and not “G”?
Many element symbols come from Latin or other older names, which is why they don’t match the English word.
| Element | Symbol | From |
|---|---|---|
| Gold | Au | Latin aurum |
| Silver | Ag | Latin argentum |
| Iron | Fe | Latin ferrum |
| Copper | Cu | Latin cuprum (from Cyprus) |
| Lead | Pb | Latin plumbum (source of “plumbing”) |
| Sodium | Na | Latin natrium |
| Potassium | K | Latin kalium |
| Tin | Sn | Latin stannum |
| Mercury | Hg | Latin hydrargyrum, “liquid silver” |
What makes gold special
- It doesn’t rust or tarnish. Gold barely reacts with air or water, which is why ancient gold objects still shine.
- It’s incredibly malleable. One gram of gold can be hammered into a sheet of about 1 square meter, thin enough to let light through.
- It conducts electricity well, so tiny amounts are used in phones and computers.
- It’s dense: a standard gold bar (about 12.4 kg) is roughly the size of a hardcover book.
Where gold comes from
Scientists think much of the universe’s gold formed in collisions of neutron stars, then reached Earth in the material that built our planet. All the gold ever mined would fit into a cube roughly 22 meters on each side.
Karats
Pure gold is 24-karat. Jewelry is often 18k (75% gold) or 14k (58.3%), mixed with other metals for strength.
Gold prices move with the economy; see why gold prices drop. The only metal that’s liquid at room temperature is mercury, symbol Hg.
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