The density of silver is 10.49 g/cm³. This physical property, specific to the pure metal, is one of the simplest and most reliable tests to check that a bar is genuine. Here’s how it works and how to use it.
What the density of silver is
Density (or specific mass) measures the mass contained in a given volume. For fine silver (999), it equals 10.49 grams per cubic centimetre at room temperature. In other words, a cube of pure silver 1 cm on each side weighs 10.49 g.
A few useful benchmarks:
- 999 silver: 10.49 g/cm³
- 925 (sterling) silver: about 10.3 g/cm³ (the added copper, lighter, lowers the value slightly)
- Pure gold: 19.32 g/cm³ · Lead: 11.34 · Tungsten: 19.25 · Copper: 8.96
These differences are precisely what makes it possible to expose a fake.
Why density exposes counterfeits
Most fake silver bars use a cheaper core metal (lead, copper, zinc, steel) coated with a thin layer of silver. But these metals have a different density:
- A “silver” bar that is lighter than expected for its volume often hides copper or zinc.
- An abnormally heavy bar may hide lead or, more rarely, tungsten (but tungsten, density 19.25, is used mainly to imitate gold, not silver).
Since it is nearly impossible to reproduce both the exact weight and volume of silver with another metal, density is a formidable filter.
How to measure the density of a bar
The method known as Archimedes’ buoyancy requires only a precision scale and water:
- Weigh the bar dry (mass M, in grams).
- Weigh it submerged in water, suspended from a thread (apparent mass M′).
- The difference M − M′ corresponds to the volume of water displaced (1 g of water ≈ 1 cm³).
- Density = M ÷ (M − M′). The result should be close to 10.49 for 999 silver.
A significant deviation (for example 9.2 or 11.5) is a warning sign. This test combines with the others described in how to recognise a fake silver bar.
The limits of the test
Density is an excellent first filter, but it has its limits:
- It doesn’t detect a fake whose core metal happens, by chance, to have a similar density (rare for silver).
- It requires a precise scale and careful handling (air bubbles, surface tension).
For a valuable bar, complement it by checking the official weight and dimensions, the hallmarks (see hallmarks of a silver bar), the seal and, with some refiners, authentication systems like PAMP’s Veriscan.
The best habit: buy certified
The surest way to avoid any doubt is still to buy from a recognised refiner (LBMA) and keep the bar in its original seal. A buy-back professional systematically checks density, weight and hallmarks before any transaction.
In summary
- The density of pure silver is 10.49 g/cm³ — a reliable benchmark.
- Simple test by Archimedes’ buoyancy: density = mass ÷ displaced volume.
- A deviation betrays a core metal (copper, lead): it’s an effective anti-fake test.
- To be complemented by official weight, hallmarks, seal and certified purchase.
Doubts about a bar? Request a free estimate; our partners verify authenticity before any buy-back. Also check the silver price.
This article is informational and does not constitute investment advice.