Types of Sapphir
Types of Sapphire
by Ardamun Ramdeva
It is estimated that over 90-95% of the sapphires in the market today are heat-treated. Sapphires are also treated by Irradiation. Pale yellow sapphires are irradiated to change them to golden yellow. This process is not acceptable as it is not stable and colors, so produced, fade in light and heat.
Summary: It is estimated that over 90-95% of the sapphires in the market today are heat-treated. Sapphires are also treated by Irradiation. Pale yellow sapphires are irradiated to change them to golden yellow. This process is not acceptable as it is not stable and colors, so produced, fade in light and heat.
Sapphires – Gemstones of the Skies
Sapphire belongs to the mineral family of Corundum. When you think of
Sapphire, you normally think of Blue Sapphire. Actually, natural sapphire
comes in a variety of colors, including red. We know red sapphire, more
commonly, as Ruby. Sapphires of all other colors are prefixed by their
colors, such as Blue Sapphire, Yellow Sapphire, etc. The other colors can be
pink, orange, yellow, golden, purple, green, and white. Another sapphire is
the exotic orange-pink known as the Padparadscha Sapphire. The major sources
for various colored sapphires are Burma (Myanmar), Madagascar, Sri Lanka,
Thailand, Australia, East Africa, and the United States.
There is a theory that heating sapphires adds to its value by enhancing its
color and clarity. It is estimated that over 90-95% of the sapphires in the
market today are heat-treated. Sapphires are also treated by Irradiation.
Pale yellow sapphires are irradiated to change them to golden yellow. This
process is not acceptable as it is not stable and colors, so produced, fade
in light and heat.
Types of Sapphire
Sapphires are extremely hard and durable, with a hardness of 9 on the Mohs’
scale. It is the hardest gemstone except diamond, which has the hardness of
10. Corundum, to which family Sapphires belong, is a natural mineral –
Aluminum Oxide. It is the rare small traces of titanium, iron, chromium and
vanadium, which create the various colors in sapphires. The rarest of all
colors is the orange-pink of the Padparadscha Sapphire – a Sinhalese (from
Sri Lanka) word meaning ‘lotus flower’. The main property of Padparadscha
sapphire is that it should display the combination of both the colors,
orange and pink, and in such a way that it should be difficult to see where
one color ends and the other starts. Experts find it difficult to agree on
the exact ideal color of Padparadscha sapphire.
Padparadschas as a collector item, are hot and snapped up as soon as
they appear. Tone and place of origin are crucial factors in determining
what is true Padparadscha sapphire. Experts believe that the tone should be
light to medium hues of sapphires from Sri Lanka (Ceylon). It has been seen
that some sapphires from Tanzania and Madagascar have been sold as
Padparadschas, but they had too much of orange-brown to be classified as
Padparadscha. The price of the unheated Padparadscha from Sri Lanka ranges
from $4,000 to $10,000 per carat.
Blue Sapphires are the most well known of all sapphires. It is
usually just known as sapphire, without any color preface. The finest of
these come from Kashmir – in India, Mogok – in Burma, and Sri Lanka. Blue
sapphires are considered the perfect and exceptional sapphires. Sapphires
look fantastic under one light condition or the other, but blue sapphires
look magnificent in all light sources. One of the largest blue sapphires
known is the Logan sapphire, weighing a massive 423 carats. This flawless
gemstone, of Sri Lankan origin, has a rich blue color and is the second
largest blue sapphire known. Cornflower blue and deep blue are the two
popular choices of blue sapphires. The intensity of blue determines its
value. The most expensive blue sapphire ever sold was the 62.02-carat
Rockefeller sapphire at $48,871 per carat.
Pink Sapphire is the second most valuable sapphire. A pure vibrant
and vivid pink color makes these gemstones exceptional. It is difficult to
decide where it stops being pink sapphire and transits into ruby. The
American Gemological Laboratories (AGL) has a grading system that draws a
line between pink sapphire and ruby. At that particular point, if the stone
is redder, it is ruby; otherwise, it is graded as pink sapphire.
Yellow, Golden and Orange sapphires are relatively less known. To
enhance their color, these gemstones are subjected to numerous treatments.
Depending on the heat treatment of pale yellow sapphire, the result may be
intense yellow, yellow/golden, golden and deep orange-like yellow colors.
Natural pale yellow sapphires are heated between 1600 to 1900 degrees
centigrade to get better shades.
Purple Sapphires are often intense electric purple or plum color.
Some have a gray or brown tinge. Exceptional one-carat purple sapphires from
Africa and Burma range from $350 to $500 per carat. Larger purples can
exceed $1200 per carat.
Color Change Sapphires are beautiful, with deep color saturation.
Sapphire is one of the gemstones that can change from one color to another,
depending on light source. Because of its atomic structure, these sapphires
look blue in daylight and seem to go purple or violet under incandescent
lights. The color change sapphire with a more dramatic change, is more in
demand. The ideal sapphire with this quality has a 100% change with two
attractive colors. One should not be able to see two colors under a single
light source. More vivid the color change, more valuable is the sapphire.
Green Sapphires come from Australia and Thailand. Presence of
black/gray secondary colors reduces its value. Pure green sapphires are also
found in Africa and greenish blue sapphires come from Burma. Top quality
green sapphires are sold for about $250 per carat.
White Sapphires were sold at a very low price of $10 per carat, until
it was realized that the process of heating changed white sapphires to
vibrant orange sapphires. Diffusion process changes these white gems to blue
sapphires. With the increase in demand for these gems, the price of white
sapphires now ranges from $100 to $300 per carat.
Star Sapphire displays a sharp six-rayed star in its center, commonly
known as asterism. It appears in bright lighting and the quality depends on
the sharpness of star, symmetry of the rays, and the body color. The
American Museum of Natural History in New York City houses the largest cut
star sapphire, the 543-carat “Star of India”, and the “Midnight Star”, a
black star sapphire.
The single most important factor in determining the value of sapphire is its
color. Even the most expensive sapphires have inclusions and are not clear
like diamonds. Fine sapphires of good color and clarity are very rare.
Sapphires with medium and dark medium tones are considered the best and the
too dark and too light sapphires have considerably less worth. The most
valuable of the blue sapphires is actually violet-ish blue.
Geological and Other Trivia
Sapphire deposits in Sri Lanka, Madagascar, Australia, Antarctica, Kenya and
Tanzania are geologically related, as all were connected, billions of years
ago, in a super continent called Pangaea. Sapphires, as well as other
gemstones, from the same source were deposited throughout this super
continent as alluvial gravels. Sri Lanka is known to be closest to this
ancient geological source, as the largest sapphires, with better
crystallization, are found there. Sapphires in Madagascar and Tanzania are
smaller in size, due to the distance they had to travel.
Sri Lanka produces the largest and finest sapphires in the world and
sapphires of almost every color is found there.
Certain people believe in the healing and astrological properties of
sapphire. Sapphire is the birthstone of people born in September and a 5th
and 45th anniversary gift. It is believed that dark blue sapphire will
enhance one’s full creative potential. The inspiration of light blue
sapphire brings in new thoughts or ways of thinking. Green sapphire allows
one’s life to run smoothly and rightly. Orange sapphire does not allow you
to deceive yourself at any level and helps you learn true knowledge. White
sapphire is a personal stone and assists you in protecting yourself from
needless sufferings. Yellow sapphire connects you with all of your inner