Difference between revisions of "Sapphire"

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[[image:Distorted_guest_crystal_in_untreated_Burmese_pink_sapphire.jpg|thumb|left|250px|Distorted guest crystal (possibly calcite) in un-treated Burmese pink sapphire.]] <br clear="left" />
 
[[image:Distorted_guest_crystal_in_untreated_Burmese_pink_sapphire.jpg|thumb|left|250px|Distorted guest crystal (possibly calcite) in un-treated Burmese pink sapphire.]] <br clear="left" />
 
[[image:Silk_&_guest_crystals_in_un-heated_Burmese_pink_sapphire.jpg|thumb|left|250px|Silk and guest crystals in un-treated Burmese pink sapphire.]] <br clear="left" />
 
[[image:Silk_&_guest_crystals_in_un-heated_Burmese_pink_sapphire.jpg|thumb|left|250px|Silk and guest crystals in un-treated Burmese pink sapphire.]] <br clear="left" />
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[[image:Unusual_cluster_of_rutile_silk_in_un-treated_Madagascan_pink_sapphire..jpg|thumb|left|250px|Unusual  cluster of rutile silk in un-treated Madagascan pink sapphire.]] <br clear="left" />
 +
[[image:Calcite_guest_crystal_in_un-heated_Madagascan_pink_sapphire.jpg|thumb|left|250px|Calcite  guest crystal in un-treated Madagascan pink sapphire.]] <br clear="left" />

Revision as of 07:10, 6 March 2007

Sapphire
Chemical composition Al2O3
Crystal system Trigonal
Habit Prismatic, tabular
Cleavage None, may show parting on twinned stones
Fracture Conchoidal
Hardness 9
Optic nature Uniaxial -
Refractive index 1.762-1.770
(+.009,-.005)
Birefringence 0.008-0.010
Dispersion Low, 0.018
Specific gravity 4
Lustre Vitreous
Pleochroism Moderate to Strong
Cornflower Ceylon sapphire
Sapphire is an aluminum oxide occurring in every color of the rainbow. When it is red, it is termed ruby. It is a stone of great hardness and durability. It can also have phenomenal characteristics like asterism (star sapphire) and color changing (like alexandrite). The color changing varieties are mesmerizing, having the ability to change color depending on whether they are viewed in daylight or incandescent light.

Spectrum

Spectrum of dark blue, green and Australian yellow sapphire.

Sapphire history

The name is derived from the Greek word "sappheiros" meaning "blue". The history of sapphire dates back to at least the 7th century BC, when they were used by the Etruscans. The sapphires used by the Etruscans, Greeks and Romans were imported from India (what is now Sri Lanka). Sapphires were reputed to protect kings from harm and envy. In the 13th century, it was written that sapphires had the power to protect against poverty, to make a stupid man wise and an irritable man good-tempered.

Sapphire mining

Kashmir, Burma, Sri Lanka, Madagascar, Australian, China

Sapphire Phenomena

Star

12 ray star sapphire
Photo courtesy of
Wild Fish Gems

Color change

Color change effect in Sapphire
Photos courtesy of The Gem Trader

Cat's eye.

Trapiche

Inclusion Images

Distorted guest crystal (possibly calcite) in un-treated Burmese pink sapphire.

Silk and guest crystals in un-treated Burmese pink sapphire.

Unusual cluster of rutile silk in un-treated Madagascan pink sapphire.

Calcite guest crystal in un-treated Madagascan pink sapphire.