I took my new diamond/gemstone tester on a visit to my family and they wanted me to try it out on some of their stones. I tried it on some that were known to be diamonds, but the tester was not saying diamond. This model of diamond/gemstone tester does refer to a possibility of being out of calibration if it undergoes too much heat and provided a calibration procedure that I followed. After the calibration, I re-tested their stones and they read diamond. I tested other types of stones and they read correctly for amethyst, quartz, ruby, topaz... One larger stone in a ring of my mother's that she had been told was Cubic Zirconia ended up registering as a diamond and she was quite pleased. Another stone that she had purchased as being an amethyst ended up registering as sapphire.
After the calibration, I re-tested the stones in the gold rings I had found, and three rings came up as diamond rings!
The diamonds were all very small stones. One ring tested as having a ruby surrounded by small diamonds. The larger stones in the other rings all came up with a glass reading which also seems to be the reading for Cubic Zirconia since my mother had a CZ ring that read as glass.
My father who has now been married over 50 years and has not taken his wedding band off for years just in the past month had to have his ring cut off because of swelling in his fingers. One of the CZ rings I had found was just the right size for him, so I ended up giving that to him.
All in all, this ended up being a very productive week at the oceanfront!!
After the calibration, I re-tested the stones in the gold rings I had found, and three rings came up as diamond rings!

My father who has now been married over 50 years and has not taken his wedding band off for years just in the past month had to have his ring cut off because of swelling in his fingers. One of the CZ rings I had found was just the right size for him, so I ended up giving that to him.
All in all, this ended up being a very productive week at the oceanfront!!