Gem treatments are controlled processes that improve a stone's color, clarity, durability, or appearance. Common accepted treatments include heat, irradiation, fracture filling (with oil, resin, or glass), diffusion, dyeing, and coating. These have been practiced for centuries and are standard when fully disclosed per GIA and international trade guidelines.
Treatments do not change the fundamental mineral species but modify optical or structural properties. Detection relies on microscopic examination of altered inclusions, spectroscopic signatures, and trace-element mapping. Full disclosure protects consumers and maintains market integrity; undisclosed treatments constitute fraud.