Just being a precious or semi-precious stone doesn’t make a stone valuable. All Sapphires or Opals aren’t valued at the same rate. There are several other factors that contribute to the price of a gemstone.
Generally, gemstone organizations around the world grade the stones based on the “four C’s”. These include the COLOR, CLARITY, CUT, and CARAT.
This article will focus on Clarity and how it affects the grade and value of a gemstone.
For starters, clarity can be explained as the number and nature of flaws in a transparent stone. These flaws can be anything that acts as an obstacle in the path of light passing through the stone. Depending on the characteristics of the obstacles, the visual appearance of the stone varies.
Amidst the professional community, these ‘flaws’ are known as ‘inclusions’ or ‘blemishes’. Inclusions are the internal imperfections of the gemstone whereas blemishes are the external imperfections.
These aren’t necessarily negative features of a gemstone, but they do affect the overall quality which inherently impacts the price.
The Most Common Types of Inclusions
The most common types of inclusions found in various gems are:
- Needles: These are the mineral fibers formed during the crystallization process.
- Crystals: Small crystal-like shapes within the belly of the host (gemstone).
- Pinpoints: Tiny crystals formed during the crystallization process inside the Gemstone.
- Feathers: Naturally occurring imperfections in atomic planes of the crystal.
- Fingerprints: Partially healed breaks on a gemstone’s surface. The fault can be on the interior or exterior surface.
- Color zoning: Color zoning is not generally considered as an imperfection. Depending on the zoning intensity (i.e. minute, minor, obvious or prominent), the stone’s price can get affected. However, for some gemstones, a fair amount of color zoning is seen as an attractive feature.
GIA Clarity Grading Scale
The Gemological Institute of America (GIA) has set a clarity grading standard for various gemstones. These are Type I, Type II, and Type III. Where, Type I stones are pure or extremely clean in nature. Type II stones are grown naturally but have minor blemishes. Type III stones have a high amount of blemishes and thus very low price. They are usually not used for adornments; they primarily serve industrial purposes.
All these types have further levels for determining the quality & standard of a gemstone. These include:
Very Very Slight inclusions (VVS): The rating is used for stones with very few inclusions on the internal and external surface. These stones form 10 percent of the total market of quality stones. The inclusions are impossible to be seen with a naked eye.
Very Slight (VS): The rating is used for stones with slightly more inclusions than the previous level. These account 10 – 30 percent of the stones in the market.
Slight Inclusions (SI): Inclusions in these type of stones are far more visible to the naked eye.
Imperfect (I): These are the least demanded stones in the market and are priced the lowest as well.
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