Facts about Sapphire
Australia leads the world in sapphire production, specifically from basalt-derived placer deposits in Queensland and New South Wales.
A sapphire (from the Latin sapphirus and Greek sappheiros, perhaps derived from the Hebrew word ?????, sapir) is a gemstone belonging to a family of gems that are varieties of the mineral corundum.
Purple sapphires, lower in price than blue ones, contain the trace element vanadium and come in a variety of shades.
Sapphires are part of the crown jewels of royalty and are a mark of wealth and luxury.
Sapphires that are not blue are referred to as "fancy sapphires."
Some "color-shift" sapphires are blue in outdoor light and purple in indoor lighting.
According to Rebbenu Bachya, the word sapir in the scriptural writing of Exodus 28:20 means "sapphire" and was the stone on the Ephod representing the tribe of Issachar.
Sapphires have a hardness of 9.0 on the Mohs scale of mineral hardness.
The world's largest and most famous star sapphire is the "Star of India," a blue stone that weighs about 563 carats.
Wafers of single-crystal sapphire are also used in the semiconductor industry as a substrate for the growth of gallium nitride based devices.
Historically, most sapphires have been mined in Sri Lanka, Madagascar, and Myanmar.
Upon magnification, a sapphire may be seen to contain white, needle-like structures known as "silk."
The value of a star sapphire depends not only on the carat weight of the stone but also the body color, visibility, and intensity of the star.
Some sapphires are heat-treated or otherwise enhanced to improve their appearance and color, though some people object to such practices and prefer natural, untreated stones.
Sapphires (as well as rubies) can be found in various rocks, mainly those of igneous or metamorphic origin (Sethi 1997).
The titanium-sapphire laser is popular because it provides the relatively rare ability to tune the laser wavelength in the red-to-near-infrared region of the electromagnetic spectrum.
Pure sapphire ingots can be sliced into wafers and polished to form transparent crystal slices.
White sapphires usually come out of the ground as light gray or brown and are then heated to make them clear; but in rare circumstances, they are found in a clear state.
Gem-grade sapphires and rubies are also found in and around Franklin, North Carolina.
Pink sapphires have traces of chromium; the deeper the pink, the higher the value of the stone, as long as the color goes toward the red of rubies.
Synthetic sapphire crystals can be grown to form large, cylindrical crystal ingots ("boules"), up to many inches in diameter.
The term settling velocity (or fall velocity or terminal velocity (ws)) of a particle of sediment is the rate at which the particle settles in still fluid.
Such surfaces often contain materials (including silicon carbide) that, like diamond, are harder than sapphire and capable of causing scratches (Scheel 2003).
A star sapphire is a type of sapphire that exhibits a star-like pattern known as "asterism."
Yellow and green sapphires have traces of iron, which gives them their color.
Titanium and iron inclusions within the aluminum oxide result in various shades of blue sapphires.
Some "color-shift" sapphires are blue in outdoor light and purple in indoor lighting.
Sapphire ranks high on the Mohs scale of hardness, but owners of such watches should be careful to avoid abrasion against diamond jewelry, artificial stone, and simulated stone surfaces.