GemsLabé
Gemstone Identification Report
Report №
082-2026
Conclusion
Sapphire, Corundum
Heat treatment · origin Sri Lanka
01Identification
- Species
- Sapphire, Corundum
- Origin
- Sri Lanka
- Treatment
- Heat treatment
02Measurements
- Shape & cut
- Oval
- Weight
- 0.770 ct
- Dimensions
- 6.14 × 5.09 × 3.15 mm
03Optical & physical tests
- Refractive index
- 1.760 - 1.768
- Double refraction
- 0.009
- Polariscope
- Doubly Refractive
- Pleochroism
- Moderate violetish blue to light greenish blue
- Fluorescence LW 365 nm
- inert
- Fluorescence SW 254 nm
- inert
- Chelsea filter
- No reaction
Microscope
A minute crystal inclusion exhibiting a characteristic discoid halo fracture pattern — consistent with so-called 'snowball'-type inclusions — in which the surrounding partially healed discoid fractures provide evidence of exposure to high-temperature thermal enhancement.
Comments
Thermal enhancement (heat treatment) of corundum is a widely accepted and commercially established standard practice within the international gem trade, provided it is fully and transparently disclosed to all parties throughout the chain of custody.