What is a sapphire?
A: Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminum oxide (α-Al2O3) with trace amounts of elements such as iron, titanium, chromium, vanadium, or magnesium.
The name sapphire is derived from what?
A: The Latin "saphirus" and the Greek "sapheiros", both of which mean blue.
It is typically blue, but natural "fancy" sapphires
also occur in what other colors?
A: Yellow, purple, orange, and green colors; "parti sapphires" show two or more colors.
Red corundum stones also occur but are called what?
A: Rubies rather than sapphires.
Pink-colored corundum may be classified as what?
A: Either as ruby or sapphire depending on locale.
Commonly, natural sapphires are what?
A: Cut and polished into gemstones and worn in jewelry.
They also may be created synthetically in laboratories
A: Industrial or decorative purposes.
Because of the remarkable hardness of sapphires – 9 on
the Mohs scale (the third hardest mineral, after diamond at 10 and
moissanite at 9.5 – sapphires are also used in what?
A: Some non-ornamental applications, such as infrared optical components, high-durability windows, wristwatch crystals and movement bearings, and very thin electronic wafers.
They are also used as the insulating substrates of
special-purpose solid-state electronics such as what?
A: Integrated circuits and GaN-based blue LEDs.
Sapphire is the birthstone for what month?
It’s the gem of the 45th what?
A sapphire jubilee occurs after how many years?
Sapphire is one of the two gem-varieties of what?
A: Corundum, the other being ruby (defined as corundum in a shade of red).
Blue is the best-known sapphire color, but they occur
in other colors, including what?
A: Gray and black, and also they can be colorless.
Sapphire and rubies are often found in the same
geographical settings, but they generally have different what?
A: Geological formations.
For example, both ruby and sapphire are found in
Myanmar's Mogok Stone Tract, but the rubies form in marble, while the
sapphire forms in what?
A: Granitic pegmatites or corundum syenites.
Every sapphire mine produces a wide range of what?
A: Quality, and origin is not a guarantee of quality.
For sapphire, who receives the highest premium?
A: Kashmir, although Burma, Sri Lanka, and Madagascar also produce large quantities of fine quality gems.
The cost of natural sapphires varies depending on what?
A: Their color, clarity, size, cut, and overall quality.
Geographical origin has a major impact on what?
For most gems of one carat or more, an independent
report from a respected laboratory such as GIA, Lotus Gemology, or SSEF, is
often required by whom?
A: Buyers before they will make a purchase.
Sapphires in colors other than blue are called what?
A: "Fancy" or "parti-colored" sapphires.
Fancy sapphires are often found in what colors?
A: Yellow, orange, green, brown, purple and violet hues.
Gemstone color can be described in terms of what?
A: Hue, saturation, and tone.
Hue is commonly understood as what?
A: The "color" of the gemstone.
Saturation refers to the vividness or brightness of
A: The hue.
Tone is the lightness to darkness of what?
A: The hue.
Particolored sapphires (or bi-color sapphires) are
those stones that exhibit what?
A: Two or more colors within a single stone.
The desirability of particolored or bi-color sapphires
is usually judged based on what?
A: The zoning or location of their colors, the colors’ saturation, and the contrast of their colors.
Colorless sapphires have historically been used as
A: Diamond substitutes in jewelry.
A star sapphire is a type of sapphire that exhibits
A: A star-like phenomenon known as asterism; red stones are known as "star rubies".