About Jools | About Diamonds | About South Sea Pearls | Pearl Sorting and Grading
There are a few steps involved with sorting pearls.
Firstly, the pearls are sorted according to whether they can be used for the cultured pearl industry or not. Those that can be are categorised into 3 sections:
a) Unmarked pearls
b) Pearls with one major blemish
c) Pearls with more than one major blemish
A sieve is then used to separate different pearl sizes, and then graded based on the following considerations:
- 1. Thickness of nacre: This is determined by the length of time in which the pearl has been in the oyster. The thicker the nacre, the more expensive the pearl will become.
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2. Lustre: The lustre of a pearl is concerned with the effect of reflection and refraction from the inner layers of skin as well as the surface.
Lustre is defined as exceptional, fine or dull.
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3. Colour: South sea pearls come in various hues of black, white and gold.
Pearls come in a wide variety of colours.
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4. Shape: There are many different shapes of pearls. The most frequently found are round, half round, egg, pear, button, girdled, baroque and semi baroque; the most rare and sought after being round and tear drop shaped pearls.
Pearls also come in a wide variety of shapes.
- 5. Surface perfection: This refers to whether the surface of the pearl has any marks or blemishes. The cleaner the surface of the pearl, the more valuable it is. There are 4 classifications:
- Clean: pearls can be blemish free or contain minute surface characteristics that are very difficult to see
- Lightly Blemished: minor blemishes or surface irregularities
- Moderately Blemished: noticeable surface characteristics
- Heavily Blemished: obvious surface irregularities.
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6. Size: Australian pearls dominate the pearling industry in size and quality. The average size for Australian pearls is 10-14mm, although some extremely rare pearls have reached an incredibly large 20mm in diameter.
Pearls range in size from 8mm to 18mm.