Gemstone Reports

Glass Imitations of Gemstones

Growth or Treatment: Pulled

Identification Tools Required: Magnification

How to Identify: 

Primary Test: Glass has confused more than one gemologist simply due to the fact that it is not  an imitation that one expects to see very often in jewelry. Magnification is key because of two issues: #1 Glass will almost always have gas bubbles that are unusual for the type of stone being emulated, and generally are far too large to be in any kind of natural gemstone. #2 Glass breaks in a classic conchoidal break pattern that is difficult to find in natural gemstones. Between the two of these glass is generally a fairly easy identification.

Secondary Tests: While a low refractive index can be a good indicator for glass, one must remember that the RI readings of glass can vary widely. So there is no set number for the expected RI of glass and that test cannot be considered diagnostic, only secondary.

Repair and Setting: No special care required other than for any glass imitation. Extreme heat may cause cracking or complete disintegration. Should not react to cleaners or ultrasonic.



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