5 ms·

Nonsense. The average person, me included, could not detect impure gold if given a piece of it.

• dnautics 9y ago
  It's not that hard. Take a Black Rock, and a few samples ok known purity, 75,80,95,100%. Then scratch the gold sample across a set of lines, of these purities, and see which is the closest.
  • 21 9y ago
    You failed. A lot of counterfeit gold has insertion of other metals in the center (tungsten for example which has a similar density) https://static6.businessinsider.com/image/505a1d2eeab8ea8610000007-480-640/fake-gold-bar.jpg https://static6.businessinsider.com/image/505a1d2eeab8ea8610...
    • lightedman 9y ago
      Tungsten is noticeably lighter, by about 7%. Hand-in-hand comparison with another similar-sized bar of pure gold would give it away instantly.
      • 21 9y ago
        Note that I specifically talked about density, not weight. Wikipedia: Because the density is so similar to that of gold (tungsten is only 0.36% less dense), tungsten can also be used in counterfeiting of gold bars, such as by plating a tungsten bar with gold
        • lightedman 9y ago
          That wouldn't pass the scratch test mentioned above. The gold plating would wear off (and gold doesn't hold well to tungsten, usually requiring an intermediary layer like titanium or copper.)