This is because the color change of most jewelry is caused by radiation and heat treatment. However, it is not easy to detect whether the irradiated jewelry changes color under ordinary equipment, because it will be marked "the reason for color change is undetermined". In this case, you can choose an authoritative organization with professional testing equipment for re-inspection.

Extended data

In order to make the color or purity of gems more perfect, you can put a variety of gems into the furnace to heat them and see if you can achieve better results. Common gemstones that can be heat treated are ruby, sapphire and tanzanite.

After heating, the crystal appears purplish pink, both of which are very popular in the market. The heating of topaz is mainly to remove the yellow component and enhance the pink color, mainly for some yellowish or brownish topaz. At present, most natural pink and red topaz are heated by yellow topaz from Brazil.

Heating can change the color of tourmaline. Generally, dark tourmaline can produce green to blue-green when heated. Powder or red tourmaline can produce colorless, orange tourmaline can produce yellow, brown and purple tourmaline can produce blue. The color of tourmaline after heat treatment is stable and unpredictable.

Phoenix Net-GRC takes you to know about jewelry appraisal.