As rumours that gold bars may in fact be gold plated tungsten have surfaced, here’s a simple way to test your gold for purity. Gold has a specific gravity of 19.32 (tungsten is 19.60). A 1 ounce gold coin (28.3495 grams) when placed in water will displace an extra 1.467 cc of water, 29.8165 cc (tungsten an extra 1.446 cc – 29.7955 cc). Tungsten displaces less water than gold. The more you have, the easier it is to detect.
One ounce of silver will displace an extra 2.70 cc of water – 31.0495 cc (in case you wondered).