Geology Home Page physical geology historical geology planetary gems
Roger Weller, geology instructor
by Katie Bock
As colorful as the rainbow, so are the different varieties of sapphires.
Blue, pink, orange, violet, white and yellow are only some of the colors of
these precious stones. Not only are there a wide spectrum of colors, but there
are also different types of sapphires namely, the Kashmir sapphire, the
Padparadascha, the star-shaped sapphire and the color changing sapphire.
The sapphire is a translucent to transparent, non-red form of the mineral corundum. The common blue sapphire receives its coloring from iron oxides and titanium. They are heat treated to intensify the blue color and to bring clarity by removing any impurities. On Moh’s scale of hardness it reaches a nine which makes it the second hardest mineral on earth. Because of its durability, sapphires are used immensely in jewelry especially in engagement rings. The sapphire is considered a sacred stone and “symbolizes sincerity, truthfulness, and faithfulness.” (http://www.associatedcontent.com, Charlotte Kuchinsky) According to mythology, it was considered to bring enlightenment and healing to diseases such as rheumatism or colic.
TOP FOUR SAPPHIRES-
The Kashmir Sapphire:
(Photo: ©1986 Tino Hammid; gem: Meyer & Watt)
This sapphire, also known as the “cornflower blue” sapphire was named for its
color resemblance to the cornflower plant.
It was primarily mined in Kashmir, India high up in the Himalayan Mountains. This sapphire became the standard by which all other blue sapphires are measured today because of its quality in color and clarity. It is extremely valuable because it is almost impossible to find these anymore.
The padparadascha sapphire received its name by Sri Lankans because of its similarity in color to the lotus blossom.
It was heavily mined in Sri Lanka but also in Africa and Australia. This stone gains its value from its scarcity and rarity in color. Real padparadaschas have a watermelon coloring and can range in price from $5000 to $30,000 dollars “depending on the size, color, tone, cut, and clarity.” (Wikipedia, “Padparadscha”)
The Star Sapphire:
When sapphires are cut into a cabochon shape, a star like shape is found known as asterism. The star commonly has six legs but can also have twelve. What causes this shape is the “light reflecting off tiny inclusions in the stone.” (www.gemstone.org, “Star Light, Star Bright”) The value of this stone varies upon the clarity of the color and the brilliance of the star.
The Color Change Sapphire:
This sapphire is an extreme rarity because of its color changing properties.
When under natural, incandescent lighting the sapphire may be a simple blue.
However, put it under fluorescent or ultraviolet light and it changes to a
violet or purple color. The color change may also be a simple change in the
shade of its original color. If the change in hue is dramatic, then the stone
increases in value.
As it turns out, the sapphire is not only beautiful, but is a fascinating stone with all of its colors and types. It has stood the test of time, partly because of its durability, and continues to dazzle the human race with its brilliance.