A careful perusal of Ebay makes it quite evident that there are many fake silver bars floating on the market. Chinese made fake precious metal coins and bars are being sold on on the internet. Obviously buying from a reputable vendor is a good idea. Even if you buy from a reputable vendor what if they have been gamed successfully? They would have a set of tests that any reasonably good engineer could probably design a product that would fool them. It pays to be able to spot the real thing yourself.
- Wikipedia:Ag – has a long list of the physical properties of silver
- WikiHow: wikiHow to Test Ag
- Google: how to test if Ag bars are real
- How to test Ag – Acid test
- Ebay: GOLD TEST ACID 10K 14K 18K 22K Ag Platinum testing kit + Stone + Wooden Box
- Wikipedia: Electrical resistivity and conductivity
- Ag Conductivity
- Density of metals
- Detecting Fake Gold & Silver With Magnetism Can Be Easily Done For Under 50 USD
Tests completed on SD Bullion Proclaim Liberty 10 oz Silver Bar
- Density test – See spread sheet above. Calculated = 10.53 grams / cc. Reference value = 10.49 grams / cc
- Bleach test – tarnished
- Cursory ice melt test – melted quickly
- Rare earth magnet test – no attraction and you can feel the eddy currents resisting lateral movement. Not conclusive as is.
Possibly More exhaustive tests These would require much more careful engineering to insure usuable results.
- Ultrasound imaging
- Thermal conductivity
- Heat capacity testing
- Thermal imaging while on a hot or cold plate
- Electrical conductivity
Measuring the specific gravity of an object with irregular geometry
Cody tests a 1 ounce bar – bars when they are minted become work hardened. In order to fully experience the softness of gold it has to be heated up till glowing just short of melting and then allowed to air cool.
Gold carat rating table