Read About Sapphire Clarity

By John S Stewart


After colour the second most important factor when choosing Sapphire Pendants, Sapphire Rings, Sapphire Pendants and all other Sapphire Jewellery is clarity, then carat (weight) and finally cut.



Gemologists use the amount of inclusions in a stone to determine the gems natural origin or not, and these characteristics then determine the quality. Blue sapphires tend to have more internal inclusions than the fancy sapphires. Any natural defects that effect the surface of a gems are said to be blemishes.

Clarity Properties

The Gemological Institute of America has successfully been used in the classification of clarity in gemstones in following format:

VVS - Very, very slightly included - has minor inclusions that can be seen under 10x magnification, but invisible to the naked eye. No effect on appearance. VS - Is very slightly included - noticeable inclusions not likely to be visible to the unaided eye, but easily seen under 10x magnification. Little or no effect on brilliance. SI1 - Is slightly included - large or numerous inclusions that can be easily seen under 10x magnification. These inclusions are apparent or somewhat apparent with the naked eye. Slight effect on appearance, but little or no effect on brilliance. SI2 - Is slightly included - obvious inclusions that can be easily seen under 10x magnification. Slight effect on appearance and brilliance. I1 - Obvious inclusions - significant effect on appearance, brilliance and transparency. I2 - Prominent inclusions - significant effect on appearance, brilliance and transparency. I3 - Numerous and prominent inclusions - severe effect on appearance, brilliance and transparency.

Inclusions in Sapphire

Sapphire inclusions can be broken down in to the following categories:

Crystals - solid inclusions being of various shapes and sizes. Extremely small crystals are known as pinpoints or grains. Silk - fine fibres of titanium dioxide (called rutile) or other minerals that can resemble the look of silk. Well-formed silk can indicate that the sapphire has undergone no heat enhancing treatment and is of a natural origin. Silk is the preferred inclusion found in sapphires. Needles - long and thin inclusions of either crystals, or tubes filled with gas or liquid (called growth tubes). Cracks - these are feather-like inclusions, called fractures or fissures. Parting - showing breakage along a plane of weakness in the stone. Twinning - when two crystals have grown out of one another or from next to each other. Halos - are circular fractures surrounding a crystal. Fingerprints - very common in sapphires. These inclusions look like being human fingerprint outlines. Colour zoning - showing uneven colour distribution in the sapphire. Cavities - when holes are extending into the sapphire from out of the surface. Chips - broken off pieces are found along the girdle or top of the sapphire.

Surface Blemishes of Sapphire

The surface blemishes found on sapphires are as shown as follows:

Scratches - lines present. Pits - tiny holes. Nicks - broken areas of the girdle or facet. Abrasions - rough scrapings on facet edge.

Sapphire Transparency

The transparency (often forgot about when grading sapphire gemstones), is the visibility that is apparent through the stone. It can be graded in the following way when viewing through the stone:

Transparent - clear and distinct. Excellent brilliance despite any inclusions present. Semitransparent - slightly hazy or blurry. Translucent - difficult to see through. Light will pass through in a diffused state. Semi-translucent or semi-opaque - a small portion of light passes through only. Opaque - almost no light will be able to pass through.

I hope that this article on the clarity of sapphires can be of some help to you.




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