History of Blue Sapphire
The name ‘Sapphire’ originates from the Latin ‘sapphires’, meaning blue. This name is believed by some to originate from either the Hebrew 'sappir' (precious stone) or the Sanskrit 'sanipriya'. The reflections of Sapphire is believed by ancient Persians to give the sky its colors. While in Greek mythology it is said the Prometheus was the first to wear Blue Sapphire. As one of the 12 gemstones set in the foundations of the city walls of Jerusalem, sapphire is linked to the Apostle St. Paul.
Blue is indeed the best-known and the most valuable of sapphire colors. The prized Kashmir and Burmese sapphires have a deep blue that is described as both intense and velvety. These sapphires are not often seen on the market today. Sri Lankan and Madagascar sapphires are the most common today, with a wide range of colors from light blue to dark blue. With blue sapphire, the intensity of blue is the most important factor. For example, a huge sapphire with a washed-out, weak blue color is much less valuable than a much smaller stone of excellent color. An intense, rich pure cornflower blue that is not too dark or too 'inky' is the most desirable color. Overall, sapphires that are too dark or too light in color are less valuable, but light-blue sapphires often have greater brilliance that is rarely found in darker blue stones. Colorless sapphires are actually quite rare, since most stones will exhibit some faint hints of color. In the gem trade, when referring to sapphire, blue sapphire is the official designation; all other colors, including pink, green, orange, purple and white sapphire, are referred to as 'fancy sapphire'.
Sapphire colors are best viewed under natural daylight. In artificial or incandescent light, sapphire colors can appear darker and inky black-blue. Many may even appear redder and less attractive than they really are. Sapphire colors are a result of trace impurities. The coloring agents found in blue sapphire are typically iron and titanium. Violet stones are colored by vanadium.Pink sapphire and purple sapphire are often colored by iron and titanium impurities. Most yellow sapphire is naturally on the lighter side. It is through heat treatment that a more intense yellow golden color is produced. Beryllium-treated sapphire may result in brilliant bright yellow. Small traces of iron can cause yellowish and greenish hues in stones. Chromium is known to produce fine pinks (and red in ruby), whilst iron and vanadium together can produce lovely orange stones. Padparadscha sapphire is a very rare sapphire with a pinkish-orange hue. A true padparadscha will always have a hint of pink. Many 'green' sapphires consist of fine alternating bands of blue and yellow sapphire, which are visible under a microscope.
Sapphire Clarity and Luster
Sapphire can occur transparent to opaque. Transparent materials are the most valuable. Some translucent materials are cut into beads or cabochons. Opaque materials have very little gemstone value, although they may sometimes be used for ornamental carvings. Sapphires are generally cleaner than ruby, so it is best to look for stones that are eye-clean. Eye-clean stones in larger sizes are quite rare, especially in ideal colors. In some cases, extremely fine silk throughout the stone can enhance the value of some sapphires. The famous sapphires from Kashmir have a velvety blue color which is caused by this fine silk. This same silk causes the asterism seen in star sapphires. However, too much silk weakens the color, rendering it an undesirable grayish color. The rutile needles that are responsible for the silky shine reflect the light in sixty-degree angles. If the rutile needles are perfectly aligned in the same direction, the inclusions can result in six-rayed asterism when cut en cabochon and viewed under strong light. Sapphire exhibits an attractive vitreous luster.
Sapphire Cut and Shape
Various shapes and cutting styles are common with sapphires. Ovals, cushions, and rounds are commonly seen, as are other shapes, such as fancy hearts, pears and emerald cuts. Round stones can command very high premiums, especially in diamond-cut calibrated stones weighing 1 carat or more. Cabochons are common for translucent stones or for stones with visible inclusions. Briolettes, beads and tumbled sapphire can also be found, but is usually lower grade material.
The most common treatment for sapphire is heat treatment, though unheated sapphire specimens can be found. Stones are heated (generally before they are cut) to between 1700 to 1800 degrees Celsius (3100-3300 degrees F) for several hours. Most sapphires today are heated, and unheated stones in rich blue can command enormous prices in today's market. Some blue sapphires may also be diffusion treated, though this treatment is more common for star sapphires. Beryllium treatment is now being used to produce stunning orange and red colors that were once rarely seen. All sapphire treatments should be fully disclosed by any reputable dealer.
Composition of Blue Sapphire
Sapphire and Ruby are color varieties of the mineral Corundum (crystalline aluminum oxide). Corundum produces 'other colored' gemstones, meaning that trace amounts of elements such as chromium, iron and titanium as well as color centers are responsible for producing its rainbow of colors.
Properties of Blue Sapphire
Blue Sapphires are transparent gemstones, whose colors include blues, violet blues, greenish-blues. As with most gemstones the intense 'middle' colors are the happy medium, with pure blues being the marketplace ideal. Blue Sapphires are pleochroic meaning different colors are visible from different viewing angles. Blue Sapphires usually look their best when viewed outdoors in natural light or under fluorescent. The most prized colors of Blue Sapphire are 'royal blue' (dark blue with 10 to 15 percent violet) and 'cornflower blue' (medium blue with five to 10 percent violet).
While both Ruby and Sapphires are classed as Type II gemstones, meaning they typically grow with some minor inclusions in nature that may be eye-visible, Sapphires are usually cleaner (and larger) than Ruby, with an eye-clean clarity (no visible inclusions when the gem is examined six inches from the naked eye) being the typical standard. Microscopic inclusions (called 'flour', 'milk' or 'silk') in some Blue Sapphires can convey a 'velvety' or 'sleepy' appearance that increases both beauty and value.
Source of Blue Sapphire
The original source for Blue Sapphire is Ceylon, now known as Sri Lanka. Madagascar has been the new supplier for Sapphires since the early 90s. Arguably the world's finest Blue Sapphires were discovered in Kashmir (India) around 1881, although the deposit was depleted by the 1930s. Other sources for Blue Sapphire include Burma, Australia, Cambodia (Pailin), , Nigeria, Tanzania, Thailand, the U.S.A. (Montana) and Vietnam.
Spinal derives its name from either the Latin 'spina' (thorn), or the Greek 'spintharis' (spark), in reference to its bright red hues. Historically confused with both Ruby and Sapphire, Spinal occurs in a plethora of colors, including blue, orange, pink, purple and red. Available in pure blues, along with blues with violet or green tints, a variety called Cobalt Blue Spinal (colored by trace amounts of cobalt) is arguably some of its finest hues. Sources include Madagascar, Tanzania and Vietnam.
Blue Star Sapphire
A unique and rare gemological phenomenon, Star Sapphires are traditionally the most popular of all star gemstones. Due to an optical special effect called 'asterism' or the 'star effect', parallel needle-like inclusions create a reflected luminous star of light that moves across the gemstone. For Corundum, reflections from a whole host of tiny retile needle inclusions, also known as silk, cause their stars. The ultimate love charm, a Blue Star Sapphire is said to have been responsible for Helen of Troy's conquests. Historically a common talismanic gemstone, Star Sapphires are said to be a protective 'guiding star' for travelers. All star gems are dependent on a gem being cut 'en cabochon' (cut in convex form and highly polished, but not faceted). While Sri Lanka are the world's 'classic' source, once contributing 90 percent of the Star Sapphires on the market, the gem pictured hails from Madagascar.
Iolite is named after the Greek 'ios' (violet) and 'lithos' (stone). Historically compared and confused with Blue Sapphires, Isolate’s blues and transparency explains its common name, 'water sapphire'. Despite the name, Iolite is actually fairly easy to differentiate from Blue Sapphire due to its pleochroism. This means each Iolite crystal has three colors, deep blue, colorless to very slightly brown and colorless to very slightly blue, whose intensity changes when it is viewed from different angles. A beautiful gemstone in its own right, whose colors and characteristics are immediately obvious to the expert eye, Iolite is predominately sourced from India, Madagascar and Sri Lanka. Other sources include Brazil, Burma, Canada, Namibia and Tanzania.
Even though Kyanite was named in 1789 from the Greek 'kyanos', meaning 'blue', it was sold to Europeans as Blue Sapphire until the turn of the 20th century. An interesting mineralogical attribute of Kyanite is that it is a polymorph, meaning it has two different hardnesses. This makes Kyanite challenging to cut well and thus Kyantie's faceting quality is important.
Midnight Blue Sapphire
Mined in a wide variety of countries, including Australia, China, Madagascar, Nigeria, Thailand and Vietnam, Midnight Blue Sapphires are characterized by rich, deep, over-color blues. Midnight Blue Sapphires are affordably priced due to their tone and saturation reducing transparency, something that actually accentuates the gem's luster, complementing its flashes of colorful brilliance.