Gemstone Treatment

Widely used enhancement methods: Heat Treatment: Most common treatment. Heating gems to high temperatures improves color or clarity. Used on sapphire, ruby, tanzanite, topaz, and many others. Usually permanent and stable. Very difficult to detect without advanced equipment. Irradiation: Exposing gems to radiation changes color. Used on topaz (creates blue), diamonds (various colors), and pearls. Some treatments are stable, others fade over time or with heat. Must be disclosed. Fracture Filling: Filling surface-reaching fractures with glass, resin, or oil improves appearance. Common in emerald, ruby, and diamonds. Can be detected under magnification. May require special care (avoid heat, ultrasonic cleaners). Dyeing: Adding color to porous or fractured materials. Common in jade, turquoise, pearls, and some agates. Usually detectable and may fade. Less valuable than natural color. Coating: Thin films applied to surfaces to change color or add effects. Can wear off over time. Must be disclosed. Check for surface scratches or uneven color. Bleaching: Removing color from materials. Common with pearls and some organic materials. Usually stable but material may be more fragile.

The most common gem treatment: Purpose: Heat treatment improves color (removes brown tones, intensifies blue), removes color zoning, and improves clarity (dissolves inclusions, heals fractures). Process: Gems are heated in controlled furnaces to specific temperatures (often 1000-1800°C) for specific times. Atmosphere (oxidizing or reducing) affects results. Materials Commonly Treated: - Sapphire: Heat removes silk (rutile needles), improves blue color, removes brown tones - Ruby: Improves color and clarity - Tanzanite: Converts brown material to blue - Topaz: Can create or change colors - Amber: Clarifies and can create "sun spangles" Permanence: Usually permanent and stable. Won't fade or change under normal conditions. However, some heat-treated gems can be damaged by high heat (like from a jeweler's torch). Detection: Very difficult to detect without advanced equipment. Some labs can identify heat treatment, but it's not always possible. Assumed for many gem types unless proven otherwise. Value Impact: Heat treatment is widely accepted and expected for many gems. Usually reduces value compared to untreated, but treated gems are still valuable.

Filling cracks to improve appearance: Materials Used: Various fillers - oils, resins, glass, or wax. Each has different properties and durability. Emerald: Almost all emeralds are oiled (filled with oil or resin). This is traditional and expected. Improves clarity and protects fractures. May need re-oiling over time. Ruby: Glass filling is common. Fills fractures and can improve appearance. May be detectable and requires special care. Diamond: Some diamonds are fracture-filled. Must be disclosed. Requires careful handling (avoid heat, ultrasonic cleaners). Detection: Usually visible under magnification. Look for: - Flash effect (rainbow colors) in fractures - Bubbles in filler material - Different luster in filled areas - Cracks that look "healed" Care: Filled gems require special care: - Avoid high heat (can melt or damage filler) - Avoid ultrasonic cleaners (can remove filler) - Avoid harsh chemicals - May need re-filling over time Value Impact: Significantly reduces value compared to unfilled gems. Must be fully disclosed.

Changing gem colors with radiation: Process: Exposing gems to radiation (gamma rays, electron beams, or neutron bombardment) changes atomic structure, creating color centers that produce color. Blue Topaz: Almost all blue topaz is irradiated. Natural blue topaz is extremely rare. Treatment is stable and safe. Very common and accepted. Diamonds: Can be irradiated to create various colors (blue, green, yellow, etc.). Some colors are natural, others only from treatment. Requires disclosure. Pearls: Some pearls are irradiated to create gray or blue colors. Must be disclosed. Stability: Varies by material and treatment type: - Some are completely stable - Others fade with heat or light exposure - Some require annealing (heat treatment) after irradiation to stabilize color Safety: Treated gems are safe to wear. Radiation levels are low and decay quickly. No health risk from wearing treated gems. Detection: Can be difficult. Some labs can detect irradiation, but it's not always possible. Color that's too uniform or unusual may indicate treatment. Disclosure: Must be disclosed. Some treatments are expected (blue topaz), others significantly affect value.

Adding color to gems: Dyeing: Adding color to porous materials or materials with fractures. Dye penetrates into material. Commonly Dyed Materials: - Jade: Some jade is dyed to improve color. Natural color is more valuable. - Turquoise: Porous turquoise can be dyed. Stabilized turquoise (impregnated with resin) may also be dyed. - Pearls: Some pearls are dyed to create uniform color or unusual colors. - Agate: Some agates are dyed to create bright colors. Very common and usually obvious. Detection: Usually detectable: - Color may be too uniform or unnatural - Dye may concentrate in fractures - Wipe test (moistened cotton swab) may pick up dye - Under magnification, dye may be visible in pores or fractures Stability: Varies. Some dyes are stable, others fade with light exposure or cleaning. Dyed materials require gentle care. Coating: Thin surface coatings can change color or add effects. Can wear off. Look for: - Surface scratches revealing different color underneath - Uneven color or wear patterns - Different luster on coated vs. uncoated areas Value Impact: Dyed and coated gems are significantly less valuable than natural color. Must be disclosed.

Legal and ethical requirements: Legal Requirements: Federal Trade Commission (FTC) guidelines require disclosure of treatments that affect value, durability, or require special care. Sellers must disclose treatments to buyers. What Must Be Disclosed: - Any treatment that affects value - Treatments that affect durability - Treatments that require special care - Any treatment that's not permanent How to Disclose: Should be clear and prominent. Can be verbal or written. Certificates from gemological labs will state treatments. Ethical Standards: Reputable dealers go beyond minimum legal requirements. They fully disclose all treatments, provide documentation, and educate buyers. Buyer Responsibility: Ask about treatments. If buying valuable gems, get independent certification. Understand what treatments are common for the gem type you're buying. Certification: Reputable labs (GIA, AGS) will identify and disclose treatments. Certificates provide independent verification. Value Impact: Treatments generally reduce value compared to untreated gems. However, some treatments are expected and accepted (like heat treatment of sapphire). Understanding treatments helps you make informed purchases and care for your gems properly.