Author name: mj

Compare thermal screening with a tester designed to separate diamond, moissanite and white sapphire. Learn which identification questions still need follow-up.

Compare Presidium’s thermal Gem Tester II with the Duo Tester II’s additional reflectivity measurement. Learn which sample and workflow limits matter.

If your buying question is “diamond or moissanite?”, choose an instrument whose documented purpose includes that distinction. Gold Kings would shortlist the GemOro UltraTester 3+ for this task before the Presidium Diamond Mate A alone.

The Presidium Diamond Mate A works best as a repeatable screening step. Set up the sample, make controlled contact and record the displayed result before deciding whether further identification is needed.

Use the GemOro UltraTester 3+ as a controlled screening procedure: prepare the item, wait for readiness, make the specified contact and read the correct indicator. Practise the sequence before relying on it during a purchase.

Mounted settings and loose stones need different supports and access. Learn how to match the tester’s contact and holder requirements to the actual sample.

A beep when the probe touches a setting may be a metal-contact warning, not a diamond result. Stop and check both the sound and the displayed indicator for your exact tester before interpreting it.

Learn what thermal and reflectivity instruments can contribute to colored-stone screening, and why origin, treatments and uncertain results need further testing.