However, it is ethically critical for a dealer, to show the treatment done on the gemstones though trading. The type of heat remedy accomplished depends on the excellent and place of the gemstones. Heat remedy may be the therapy typically completed on Yellow Sapphire to increase their color. Almost a 60%-70% of the yellow sapphires sold in the market are heat-treated. Even on close inspection of the gem lots of remedies are challenging to find.
1. Hardness & Toughness of Yellow Sapphire:
|Hardness||9 on Mohs scale|
|Toughness||Usually excellent, but stones with large fractures, or inclusions, or some treatments, can be less durable|
2. Stability of Yellow Sapphire:
|Heat||High heat can cause change in color or clarity, and can damage or destroy fracture and cavity fillings.|
|Light||Generally stable, but irradiated yellow or orange stones fade quickly; heat from bright light can cause oil to leak or dry out.|
|Chemicals||Can harm fillings and remove oil; soldering flux containing boron, and firecoat made with boric acid powder, will etch the surface of even untreated stones.|