How do you tell what metals are by not testing them?

Question: How do you tell what metals are by not testing them?
- Keywords:
  differentiation,
  metal,
  test
Asked by anon-200280 to Rosemary, Oliver, Leigh, Jordan, Hannah, David on 9 Mar 2019.
- David Walker-Sünderhauf answered on 9 Mar 2019:
  
  Technically every way to differentiate metals (or other things) is a “test” – they just range from simple to more sophisticated 🙂 I don’t know too much about metals, but the first “test” I’d do is visual – what colour is it? And then afterwards maybe see if it’s magnetic by holding a magnet to it. Another simple “test” people do in films is biting a gold coin to see if it’s real gold: apparently gold is a bit softer than similar “fake gold” metals.

Question: How do you tell what metals are by not testing them?