Gem Education
Gem Treatments
Understanding how gemstones are treated — what's accepted, what's not, and how to protect yourself as a buyer.
Heat Treatment
Very common — ~95% of sapphiresEffect
Improves colour saturation and reduces silk inclusions. A stable, permanent treatment accepted throughout the trade.
Disclosure
Must be disclosed. Look for "No indications of heating" on a GRS or GIA report for an unheated stone.
Beryllium Diffusion
Less common, controversialEffect
Beryllium atoms are diffused into the stone under extreme heat to produce vivid orange, yellow, and padparadscha colours. Surface-level — not permanent through the full depth of the stone.
Disclosure
Must be disclosed. Dramatically reduces value compared to natural colour. Detectable only by advanced laboratory testing.
Fracture Filling
Occasionally seen in rubiesEffect
Glass or resin fills surface-reaching fractures to improve apparent clarity. Not stable — can be damaged by heat, ultrasonic cleaning, and acids.
Disclosure
Must be disclosed. Heavily discounted in the market. Common in low-grade commercial ruby.
Lattice Diffusion
Surface-level colour enhancementEffect
Chemicals are diffused into the outer layer of the stone, affecting colour only at the surface. Cutting or polishing removes the effect.
Disclosure
Must be disclosed. Acceptable only in commercial-grade stones sold at commercial prices.
Irradiation
Yellow sapphires, topazEffect
Exposure to radiation alters colour. Some irradiated colours are unstable and can fade with exposure to light or heat.
Disclosure
Must be disclosed. Permanently reduces investment grade value.
No Treatment (Unheated)
Rare and highly prizedEffect
The colour and clarity are entirely natural — exactly as the stone emerged from the earth. Carries a significant premium, sometimes 2–5× the treated equivalent.
Disclosure
Confirmed by laboratory report stating "No indications of heating". Worth paying for on significant purchases.
All our stones are treatment-disclosed
Every gem we sell comes with a major laboratory certificate that explicitly states the treatment status.
Browse Certified Stones