Whilst today's main sources of Sapphire are Africa, Australia, Myanmar (Burma),
Sri Lanka (Ceylon), Thailand and the United States (Montana, North Carolina), there
are also known Sapphire deposits in Brazil, Cambodia, India, Madagascar, Tanzania
The highest quality and most desirable Sapphires are those that originate in India,
Myanmar (Burma), and Sri Lanka (Ceylon). Sapphires from India and Myanmar (Burma),
are highly prized for their pure blue colors and stones from these regions are priced
accordingly, often at collectors prices, particularly if there is documentation
available to prove the origin of the Sapphire. Sri Lankan (Ceylon) Sapphires are
sought after for both their delightful pastel blue and fancy colored variations.
Sapphire is rated at 9 on the Moh's Scale of Hardness and is second only to the
Diamond in this regard. Sapphires therefore are perfectly suited to all jewelry
purposes / uses and is a very hard-wearing, durable and versatile gemstone suitable for everyday wear.
When thinking of Sapphire, most people immediately think of, and prefer, a blue
gemstone. Sapphire is however so much more than just a blue gem and is found in
various colors including, black, blues, browns, colorless, pink, orange, peach,
purple, voilet, white and yellow. The one color that Sapphire is not is red. Red
Corundum is what we know as Ruby. In adition to the single colors, Star Sapphires
are also available.
A Star Sapphire is a Sapphire that exhibits a star-like phenomenon (asterism). This
is caused by inclusions known as silk. When silk inclusions are abundant the Sapphire
becomes translucent or Opaque and this effects the way that the gemstone reflects
light. The effect created is a star (usually made up of six rays, but sometimes
twelve), that seems to float over the surface of the Sapphire as it is moved.
Black Star Sapphires are sometimes confused with Star Diopside stones, which are
far less valuable.
There is however one sure-fire way to determine which is which;
A Star Diposide will display a star with four rays, whereas a genuine Black Star
Sapphire will exhibit a star with six (sometimes twelve), rays. This difference
is caused by the physical make-up of each of the stones and the presence of a different
number of crystal faces for the light to refract off of.
The quality of Star Sapphires is judged primarily by taking into account the sharpness
of the star and the gemstone's overall body color. A natural, untreated Star Sapphire
with a very sharp star and a bright blue body color is extremely valuable, very
desirable and extremely hard to find.
NB: When shopping for Star Sapphires, be very cautious as synthetic Stars are very
common and cheap to produce. Generally speaking synthetic stars will appear to be
incredibly high quality, with none, or certainly very few inclusions / irregularities
and have extremely sharp stars, whereas natural gemstones often contain inclusions
/ irregularities and display slightly wavy stars. When examining the gemstone, if
you notice that the reverse has been stamped with an “L” the stone you are looking
at is most certainly a “Linde” synthetic Star.
Regardless of whether or not a Sapphire initially displayed a star, once it has
been faceted, it will no longer offer up a star. For this reason, when examining
Sapphires gemstone cutters must always take the time to look closely at the stone
and check to see whether it has enough properly orientated inclusions to form a
star. If it does, the Sapphire will be cut into a Cabochon shape, the only shape that allows the stone to display the beautiful asterism, or star.
Almost all Sapphires found on the market today have been heat-treated in order to intensify color and remove “silk”, small inclusions present in most natural Sapphires.
This method of treatment is considered permanent and color should not fade over
time. Asterism can also be produced through a process known as diffusion. Star Sapphires
that have been created this way will often be known as Linde Sapphires.
Care & Cleaning:
Sapphires are a very tough, durable gemstone and can safely be cleaned with
soapy water or commercial solvent and a brush, and can also safely be cleaned using most
modern mechanical cleaners. Do however avoid subjecting Sapphires to prolonged exposure
to strong heat or light sources, particularly with regard to some varieties of heat-treated
gems, as prolonged exposure may cause permanent
changes in coloration.