A laboratory report is the passport of a fine gemstone. Here is what each section tells you. Identification The species and variety — for example “natural corundum, pink sapphire” or “natural beryl, emerald”. The word natural confirms the stone was not grown in a laboratory. Weight and dimensions Carat weight to two decimal places and […]
Discovered in the Ural Mountains in the 1830s, alexandrite is one of the rarest varieties of chrysoberyl. Its famous colour change — green in daylight, red to purple under incandescent light — is caused by traces of chromium. Judging the change Reports describe the change as strong, moderate or slight. A strong, clean change between […]
Coloured gemstones last for generations with a little care. Emerald Most emeralds are clarity-enhanced with oil. Avoid ultrasonic and steam cleaners; clean with lukewarm water and a soft brush. Opal Opals contain water and are softer than most gems. Protect them from knocks and sudden temperature changes, and store them away from harder stones. Sapphire, […]
