How dense is pure gold?
The density of pure (24 carat) gold is 19.32 g/cm³, sometimes quoted as a specific gravity of 19.3 (its density relative to water). For comparison, lead is 11.3 g/cm³, silver 10.5 and iron 7.9 — gold is exceptionally heavy for its size, which is why a genuine gold coin or bar feels denser in the hand than people expect. Only a few metals come close, notably platinum (21.4 g/cm³) and tungsten (19.25 g/cm³).
Gold density by carat
Alloy metals are lighter than gold, so the more they dilute it, the lower the density. Typical values (they vary with the exact alloy, especially the copper-to-silver ratio and any nickel in white gold):
The water-displacement (Archimedes) test
You can estimate density at home with a kitchen scale and a cup of water:
- Weigh the dry item in grams — call this W.
- Stand a cup of water on the scale and zero it, then lower the item on a thin thread until it is fully submerged without touching the sides or bottom. The reading the scale now shows is the item's weight in water, D, in grams.
- Density ≈ W ÷ D g/cm³ (1 ml of water weighs 1 g).
Compare the result with the table above. A figure well below the value for the claimed carat suggests a lighter metal inside or a hollow section. The test works best on solid items — gemstones, clasps, hollow chains and glued components all throw it off — and a typical kitchen-scale result is only accurate to within a few percent.
Why density cannot catch a tungsten fake
Tungsten has a density of 19.25 g/cm³ against gold's 19.32 — a difference of under 0.4%, far smaller than the error margin of any kitchen-scale test. That is precisely why tungsten is used to core counterfeit gold bars: they pass a density check. Detecting a tungsten-filled bar reliably needs ultrasound (which measures the speed of sound through the metal), electrical conductivity testing, drilling, or an interior scan. In jewellery, tungsten filling is rare — brass, steel and lead fakes are far more common, and the density test catches those easily.
What the density of gold is useful for
Beyond spotting obvious fakes, density lets you estimate a piece's weight from its volume (or the reverse) without a scale, check that a bar matches its stated dimensions, and understand why bullion is made in small, heavy units. For pricing rather than testing, use the live per-gram calculator or the scrap gold page; to see how carat relates to purity, use the gold purity chart.