Sapphire-Fancy Coloured

The major fancy sapphire categories are Padparadscha, pink and purple, orange and yellow, green, and colourless and black.

Padparadscha:

Padparadscha means 'Lotus flower' in Sri Lanka's language, Sinhalese. They typically have the highest per-carat value of all fancy sapphires. Generally, the colour should be an intensely saturated combination of pink and orange hues without any noticeable brown colouring. However, the term once described colours from yellowish orange to orangy red, with a range of tones and degrees of saturation.

Sri Lanka has been a traditional source, Africa and Vietnam are now recognized as sources of beautiful padparadscha, too.

Pink and Purple:

There has been a lack of universal agreement over the borderline between pink sapphire. Today, the borderlines between ruby, pink and purple sapphires are generally accepted as follows:

• Ruby: Hue colour can be orangy-red through strongly purplish red, but the dominant colour must be red. The tone level ranges from medium to dark (5-8 on the GIA tone level scale).

• Pink sapphire: Hue level range from red to purple in light tones (2-4 on the GIA tone level scale) with weak to vivid saturation.

• Purple Sapphire: Hue level range from reddish purple to violetish purple in medium to dark tones with weak to vivid saturation.

Fine pink sapphire regularly command top prices, sometimes comparable to padparadschas. Highly saturated pinks are rare, prized hues, especially those from Sri Lanka, Myanmar and Madagascar.

The market for purple sapphire is less strong. The price difference gives an incentive to heat treat purple sapphire to achieve a more desirable pink or red hue.

Yellow and Orange:

The finest yellow sapphire is yellow to orangy yellow, with medium tone and vivid saturation. More generally, yellow sapphires range from greenish-yellow to orangy yellow in light tones and all degrees of saturation.

The finest orange sapphires are strongly red-orange with medium tone and vivid saturation. A broader definition of orange sapphire includes yellowish-orange to reddish-orange in light to dark tones and all degrees of saturation.

The yellow and orange sapphires market is less stable as consumer preference changes over time.

Green:

Green sapphires range from blue-green through yellow-green, with light to a very dark tone and usually low saturation. This variety is not very marketable, and the supply is abundant.

Colourless and Black:

The purest form of corundum is considered to be either colourless or white. It used to be used as one type of natural diamond substitute. Black or very dark blue sapphires are marketed as black sapphire, and the market is comparatively small.

Phenomenal Corundum:

Colour-Change Sapphires:

The typical colour change is from blue or violet in daylight to violetish purple to strongly reddish-purple in incandescent light. The trace element vanadium causes the colour change. Following the body colour, the strength of the colour change is the second most important quality factor affecting its value.

Star Corundum:

When corundum rough contains enough silk (tiny, needle-like inclusion oriented in several specific directions), it can be fashioned as a cabochon and show the star.

The best and most expensive star corundum is semi-transparent, with enough silk to create a well-defined star. The finest star is distinct, centred on top of the stone and visible from a reasonable distance, about arm's length. The star quality should be identical in any direction. The rays are uniform in strength and reach from girdle to girdle. They should be straight and contrast strongly against the background body colour, showing smooth movement across the surface with no dead spots.

The cabochon must have an appealing face-up appearance, with the star properly centred when the gem is upright. The cabochon's outline should be symmetrical, with fair proportions (the dome is about two-thirds of the stone's width, except black star sapphire, which may have a lower dome) and a good polish.

In general, the most-prized colours are red and blue.

Clarity:

Sapphires with extremely high clarity are rare and very valuable. They are usually expected to have some inclusions. Price can drop if the inclusions threaten the stone’s durability.

Cut:

Cutters evaluate factors like colour zoning, pleochroism, and the lightness or darkness of a stone, to achieve the best overall colour, maintain the best proportions, and retain the most weight possible.

Carat weight:

Sapphires can range in size anywhere from a few points to hundreds of carats; the price per carat increases more dramatically with larger stones and higher quality.