Things You'll Need
Instructions
Thermal Conductivity
Touch the stone to be tested with the tip of the diamond tester.
Turn the diamond tester on.
Read the results of the diamond tester. If the tester registered thermal conductivity, the stone is a topaz. If it didn't, the stone is likely an aquamarine.
Loupe
Bring the loupe as close to your eye as is comfortable without actually touching your eye.
Look at the stone carefully through the loupe.
Count the number of refraction lines you can see. If you see two refraction lines easily, the stone is a topaz.