Why treatment is used
Acid bleaching may remove brown material along fractures; polymer impregnation can fill resulting voids and improve apparent translucency. Dye can add or modify color. Coatings and heat are also encountered. The precise treatment must be described, not collapsed into “fake.”

Clues are not conclusions
Surface texture, color concentration, fluorescence or a suspiciously uniform appearance may prompt further examination. Each can also have other causes. GIA research found infrared spectroscopy decisive for polymer impregnation in the studied material.

A safer buying question
Instead of asking for a home test, ask what the seller represents the material to be, whether treatment is disclosed, who issued the report and whether the report number and described item correspond.

Research basis
Independently written from public information supplied by GIA, Smithsonian and The Metropolitan Museum of Art. GIA · Smithsonian · The Met