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Star
sapphires show a bright six-legged star in the dome of their
cabochon. The stars, like the eye of a cat’s-eye are formed
by light reflecting off tiny inclusions in the stone.
History and Lore
To
medieval Christians, the three bands that form the star in
sapphire represented faith, hope and charity.
Ancient
man that the star-sapphire was a gem of destiny and that the
star was a guiding light that could protect its wearer
against evil.
One of the
world’s most spectacular star sapphires, the 153-carat Star
of India in the American Museum of National History in New
York, was actually mined in Sri Lanka, not India.
Quality,
Value and availability
The value
of star sapphire is influenced by, first, the intensity and
attractiveness of the body colour and, and second the
strength and sharpness of the star. All six legs should be
straight and equally prominent.
The most
valued colour is pure translucent to transparent vivid blue,
which rarely appears in combination with a strong star.
Stars can
occur in all sapphire colours but it is often difficult to
see the star against pale background colours, so they are
less common.
Pale blue,
gray-blue, and dark and black colours are more common. Black
star sapphires are relatively affordable.
Star-sapphires are becoming rarer. The rough gems that can
be cut into stars are now often heated to dissolve the
rutile so that faceted sapphires can be cut instead.
Star
sapphire is cut into smooth-domed round or oval cabochons to
display the star effect.
Sources
Star
sapphire is most often mined in Sri Lanka. Thailand, Kenya,
Tanzania, Myanmar (Burma), and Australia also produce star
sapphire.
Routine Enhancements
Although
star-sapphires may be heated, like all sapphire, to dissolve
rutile and re-crystallize it to create a more attractive
star, in practice, imperfect star sapphires are more often
heated to become transparent blue sapphires instead.
Care and Cleaning
Sapphire,
like its gem sibling ruby, is the mineral corundum, which
has a hardness of 9 on the Mohs scale. Corundum is so tough
that it is used as an abrasive. As a result, sapphires are
the most durable of gems.
Clean
sapphire with mild dish soap in warm water: use a tooth
brush to scrub behind the stone where dust can collect. |
