Treatments or enhancements on the Blue sapphire stone (Neelam stone) are done to either make the color light or dark or to improve the clarity and transparency. This is obviously done so that the sapphire gemstone can fetch a better price in the market. However, it is ethically important for a dealer, to disclose whether the sapphire is heated or unheated or whether a treatment has been done on the gemstones while trading.
Heating to a very high temperature for the purpose of changing its appearance.
Heating at a very temperature in presence of coloring agents for allowing chemicals to penetrate in the stone.
Stones are filled with epoxy resin or glass OR lead glass to conceal the fractures.
Any treatment done on the stones damages its internal structure of the gemstones.
Hardness & Toughness
Hardness of 9 on Mohs scale and Toughness usually excellent but large fractures can lesser the durability.
Stability (Resistance to Heat and Chemicals)
Heat – Heat can cause change in color or clarity.
Light – Fracture filling may dry out.
Chemicals – It can harm the fillings in fracture filled stones.
Synthetic Blue Sapphire Or Neelam Stone
Blue Sapphire stone synthetics are readily available in the market. Blue Sapphire is made from flame fusion, flux, hydrothermal, floating zone many process in the market.