Primary Test: The dispersion of strontium titanite is a diagnostic “tell” for this gem material sometimes used as a diamond simulant. The refractive index is well over the limit of the refractometer, but close to a diamond, which has thrown more than one gemologist for the proverbial loop. But the extreme dispersion of the strontium titanite is a diagnostic feature that no gemologist should miss. Strontium titanite has been used as a diamond simulant for decades and will most usually be found in vintage or period type jewelry pieces.
Secondary Tests: None needed.
Repair and Setting: Just because it looks like a diamond don’t confuse it with being able to take diamond type setting and repair stress. Should be removed or heat sinked before any prong repair. Not recommended for heating by torch or ultrasonic solution.