There is no trustable portable gemstone tester. There are dozens of models, but they are actually hardness testers, which does not prove the authenticity of a stone.
Unfortunately, this is one of the most frequently tool used by gemstone sellers.
If you look at the picture you will see a ruler with numbers starting from the left to the right by 1, 2, 3, 4, 5 ….
LEDs light up when you touch the surface of the stone. You can see the number that corresponds to the hardness of the stone.
This information is accurate. This is the scale of hardness, also called Mohs scale
Examples of Mohs scale hardness
1 – Talc
2 – Gypsum
3 – Calcite
4 – Fluorite
5 – Apatite
6 – Feldspar Orthoclase
7 – Quartz
8 – Topaz
9 – Corundum
10 – Diamond
The Mohs scale of mineral hardness is based on the ability of one mineral sample. The samples of matter used by Mohs are all different minerals. Minerals found in nature are chemically pure solids. Also one or more minerals make rocks. As the hardest known naturally occurring substance, when Mohs created the scale, diamonds are at the top of the scale. The hardness of a material is measured against the scale by finding the hardest material in the stone, compare to a softest material by scratching the material. For example, if some material can be scratch by apatite but not by fluorite, its hardness on the Mohs scale would fall between 4 and 5.
The hardness of a stone is due to its chemical composition
Since a synthetetic stone has the same chemical composition as a natural stone, this tool will show you exactly the same result for a natural or synthetic stone.
Therefore, natural or synthetic diamond will show you 10. Natural or synthetic ruby will also show you 9. Same for natural or synthetic sapphire: 9. Also for natural or synthetic quartz: 7 …
If you are interested in this topict, want to go from theory to practice, we offer gemology courses.