false doublet

gem

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Last updated

June 26, 2026

Quick Summary

A false doublet is a type of assembled gem, meaning it's a cut jewel made from two or three pieces of stone cemented together to appear as a single, larger, and more valuable gem. Specifically, a false doublet is constructed with two different materials. The upper part (crown) is made of a genuine gemstone, while the lower part (pavilion) is made of an inferior stone or glass.1

These gems can be detected by immersing them in a liquid with a refractive index similar to the gem fragments. The cement layer will appear as a dark line, and the different materials of the crown and pavilion will be visible. For example, diamond false doublets might have pavilions of glass or zircon, and ruby false doublets can have garnet pavilions.1

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assembled gem
…glass, it is called a false doublet. True doublets may be detected by immersion in a liquid with an index of refraction nearly the same as that of the gem fragments; the layer of cement will appear as a dark line. False doublets may be similarly exposed, but in this…
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…glass, it is called a false doublet. True doublets may be detected by immersion in a liquid with an index of refraction nearly the same as that of the gem fragments; the layer of cement will appear as a dark line. False doublets may be similarly exposed, but in this…
Read More