However, it is ethically critical for a dealer, to show the treatment done on the gemstones through 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 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 the Mohs scale |
| Toughness | Usually excellent, but stones with large fractures, inclusions, or some treatments, can be less durable |
| Refractive Index | 1.61 |
| Specific Gravity | 6.53 |
2. Stability of Yellow Sapphire:
| Environmental Factor | Reaction |
| Heat | High heat can cause a change in color or clarity and can damage or destroy fractures 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 fire coat made with boric acid powder, will etch the surface of even untreated stones. |