How to Test a Ruby Gemstone

Testing Ruby Gemstone

• 1

  Prepare the ruby for testing by cleaning it with water and a toothbrush for any hard-to-reach dirt. Proper testing will scratch the ruby, so do not test on a piece that you wish to keep intact.

• 2

  Get the glass plate out of the mineral testing kit to test the gemstone's hardness. Place the gemstone against the glass plate and drag it down slowly. If the gemstone scratches the glass plate, then it is either a genuine ruby or a spinel, which looks quite similar to the ruby.

• 3

  Get a known ruby to try the scratch test with. Should your test mineral be a spinel, then it will be scratched easily. If it is a genuine ruby, they will be identical on the Mohs hardness scale and it should not scratch deeply.

• 4

  To test a ruby without damage, a trip to a gemologist or jewelry store is in order. They can use a device called a polariscope. This is a tool that measures the refraction of light through the gemstone. A ruby will break up the light into two separate rays of light.