| Sapphires
Species: Corundum
Colour: blue in various tones, pink, colourless, yellow, orange, green, purple, and black.
Moh’s Hardness: 9
Chemical composition: aluminium oxide
September’s Birthstone
Colour/Origin
Country of origin is normally used to describe the colour of sapphires. This generalisation is both good and bad, as light and dark gems are found in all areas.
Usually the following origins are used:
(a) Sri Lankan (Ceylonese) Sapphires
Tend to be blue to violet hues and lighter in tone.
Often they are cut very deep to darken their tone, so that a 1.00ct Ceylon may look smaller than an 0.80ct Australian sapphire.
The saturation can be very intense.
 
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(b) Australian and Thai Sapphires
Tend to be darker in tone, with medium to lower saturation so that many will look black in low lighting.
Colours tend to a less attractive greenish blue and they often have a greyish steel colour (lower saturation).
(c) Burmese and Kashmir Sapphires
These are frequently described as the ideal sapphire colour. The blue hue is pure blue or very slightly violet-ish blue.
Ideally, they would have a mid tone and be very intensely saturated. Of course, not all of these gems are fine colours, and it’s only possible to prove their provenance if they have identifying inclusions.
Kashmiri gems are occasionally seen in Victorian jewellery, however there has been very little production over the last century. They are often a soft velvety colour as their brilliance is affected by clouds of “silk” inclusions, but this silky effect can give the sapphire a “blue on blue” appearance which is very attractive.
(d) Pallin and Cambodian Sapphires
Fine bright blue gems but often have obvious bands of alternating blue colour and visible inclusions.
What is the best colour?
The most preferred and valuable sapphire colour is a pure blue (to slightly violet- blue) with medium darkness and intense saturation (vividness).
There is far greater variation in sapphire colour than in rubies or emeralds. Once again, beauty is in the eye of the beholder, not what the “experts” call the best.
Origin
As stated previously, the main sapphire sources are Sri Lanka, Australia, Burma and Kashmir. Other sources of sapphires have been established in the last decade. Often dealers and marketers believe their gems fetch higher prices if they are sold under the name of a more familiar country of origin.
The use of the country of origin is more convenient and a good marketing tool. The value is simply based on attraction with only a few rare large gems fetching collector’s premiums, based on authenticated Kashmiri or Burmese origin.
If you have a sapphire you think could be from either of these sources, we can organise certification of its true origin for you by identifying their inclusions. This, however, can be a rather costly process and is usually only performed for more valuable gemstones that weigh 2 or more carats.
Shape
The shape of your sapphire is an important consideration.
Rough sapphires are often found as rounded barrel shapes to flat tabular crystals. The most economical way to cut them is into oval and cushion shapes (squarish – rectangular ovals). Unlike diamonds there is no “textbook” ideal cut standard for the proportions and angles of a sapphire.
Inclusions
Inclusions are normal characteristic of sapphires. Completely flawless stones can be costly to prove natural origin, because in general we consider very ‘clean’ gems to be synthetic or man made. Inclusions play a minor role in the value of sapphires as with other gemstones; if you cannot see them with the naked eye, they don’t really matter.
Sometimes a cloud of very fine inclusions can dull a gem’s brilliance and can lower its value. Almost all sapphires (and rubies) are heat treated; the object is to dissolve inclusions deeper into the stone. Uncut rough is placed into a furnace, often for days, and heated to remove silky clouds and to even out patchy banding. Most gemmologists accept this treatment as it is permanent, as it does not result in fading or colour change.
Famous Sapphires
Large sapphires are rare. The American Museum of Natural History owns the “Star of India” perhaps the largest cut star sapphire (536 carats) and also the “Midnight Star”, a little star sapphire (116 carats). In the United States, the heads of presidents, Washington, Lincoln and Eisenhower have been carved out of three large sapphires, each weighing roughly 2000 carats.
Padparadscha Sapphires
The rarest and most valuable fancy sapphires are the Padparadscha sapphires. This name is Sri Lankan for lotus flower, and they are found in medium orange-pink or pink-orange tones. They are thought to be more rare than fine Burmese rubies.
The most famous Padparadscha sapphire is the 100.18 carat stone in the Morgan Collection at New York’s American Museum of Natural History.
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Padparadscha Sapphires
This extremely rare and prized sapphire is a medium tone orange-pink or pink-orange stone found in Sri Lanka. Padaparadscha sapphire is probably more rare than fine Burmese ruby.
A true Padaparadscha must display a combination of both orange and pink colours. These colours should blend together, so that it is difficult to see where the pink stops and the orange begins.
It is believed the unique colour of the orange-pink padparascha sapphire comes from both iron and chromium impurities.
Burma and other sources:
Gem-quality padparadschas are rare, but fine specimens have been reported from Vietnam and, more recently, Burma. The new Nayor area in Burma is producing a few orange-pink padparadscha. Of course, these stones are more rare than the Sri Lankan material and possess the sought-after Burma pedigree.
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