Until the eighteenth century, all gems blue sapphires were
considered. With the knowledge of the chemical composition of rocks, their
crystal system, their optical and physical properties, sapphire is now
differentiated rocks of the same color and is considered a gem with its own
characteristics. The most beautiful sapphires from Kashmir
whose deposits are now exhausted. Their velvety blue color (also called
"blue-blueberry") is popular. We also located in Myanmar (Burma ),
Thailand , Cambodia , Sri
Lanka , Australia ,
and Yo go Gulch, in the state of Montana in the
United States
Sapphire is often subjected to treatments to improve its
color and transparency. The colorless or very pale blue tint is exceptional
when heated in a dye composed of iron and titanium at temperatures approaching
their melting point (about 1800 degrees centigrade). This treatment, which
makes them lose 70% to 80% of their value, however, can be detected by an
experienced gemologist.
The blue sapphires can easily be confused with Tanzania, spinal
natural blue, iolite (cordierite) and glass. There are also a variety of colors
(pink, yellow, green and clear), the rarest and most expensive being the
undisputed " Padparadscha " fancy
sapphires that are not found in Sri Lanka and whose unique orange pink hue evokes
the most beautiful sunrises.
Characteristic
Chemical
composition (Al2O3): Aluminum oxide
Color: Blue
Hardness: 9.0
Specific gravity:
4.00
Refractive index:
1.76 - 1.77
Dispersion: 0018
Polychrome:
Blue-violet, blue-green
Birthstone:
September
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