Calculate the specific gravity of gold using either density or a hydrostatic air-versus-water measurement. The tool also compares the result with useful gold and gold-alloy reference values for screening and educational purposes.
Two practical calculation methods.
Specific gravity is a screening measurement. A measured result outside the expected range does not by itself identify the material.
When the air and submerged weights use the same mass units, their ratio is dimensionless. Under the simplified room-temperature reference used here, specific gravity and density in g/cm³ have the same numerical value.
Pure gold is commonly referenced at approximately 19.32 specific gravity. Gold alloys generally have lower values because alloying changes the material's density.
| Material | Approximate Reference SG | Use |
|---|---|---|
| 24K / Pure Gold | 19.32 | High-purity reference |
| 22K Gold | ~17.5 | Approximate alloy reference |
| 18K Gold | ~15.5 | Approximate alloy reference |
| 14K Gold | ~13.1 | Approximate alloy reference |
The alloy values are not universal constants because the non-gold chemistry can vary considerably.
A hydrostatic test compares an object's apparent weight in air with its apparent weight while suspended in water. The difference represents buoyant force and can be used to estimate specific gravity.
It can be useful for screening, but it should not be treated as a standalone authentication method. Hollow jewellery, stones, solder, plating, cavities and mixed materials can all alter the measured result.
A reliable authentication process may require additional methods such as electronic testing, XRF or other professional analysis.
Approximately 19.32 using water as the reference.
Use density divided by water density, or air weight divided by the loss of apparent weight in water.
No. It is a screening measurement rather than conclusive authentication.
There is no single universal value because 18K alloy chemistry varies.
No. It is dimensionless.