Sapphire is the official birthstone for the
month of September as adopted by the American National Association
of Jewelers in 1912. It is also one of the birth stones for
the Zodiac signs of Pisces, Taurus, Virgo and Sagittarius.
See the birthstone
tables for additional references to this stone. Sapphire
is given as a gem for the 5th, 23rd and 45th wedding anniversaries
while a star sapphire is given on the 65th wedding anniversary.
Sapphire is the non-red variety of corundum
(the red variety of corundum is ruby). A 9.0 on the Mohs
scale of hardness, sapphire is the second hardest natural
Blue is by far the most popular color for sapphires,
but they can be almost any color, including yellow, green,
white, colorless, pink, orange, brown, and purple. Padparadscha
is the name for a rare orange-pink variety of sapphire and
has a higher value than blue sapphires.
Sapphires with inclusions of tiny, rutile needles
exhibit an optical property called asterism. This is the star
shaped effect seen in star sapphires and is usually only seen
in cabochon cuts.
Star sapphires usually have six ray stars, but
twelve ray stars are also known. Rarely, when sapphires are
cut en cabochon, they can demonstrate a cat's eye effect.
This effect displays a thin band of light down the center
of the stone and is known as chatoyancy.
Heating colorless and very pale blue sapphires
to high temperatures is done to give them an intense blue
color This treatment can also improve the clarity of the stones
by removing tiny inclusions.
A rare variety of sapphire, known as color changing
sapphire, exhibits different colors in different light. A
color change sapphire is blue in natural light, and violet
in artificial light. A similar effect is also seen in alexandrite.
Sapphire was first created synthetically in
1902 and is hard to distinguish from natural sapphires except
by gemologists. Lab grown sapphires range in price and smaller
stones are frequently used in less expensive jewelry.
jewelry made with sapphire.
A selection of other free
form cabochons and rough available for custom designed
see other September