Five S’s classification


Of all the pearls across the globe, there is one that is rare and revered. In pristine waters where the temperature is gentle and the atmosphere nurturing, there is a pearl with a strange perfection which bears the fingerprint of forever, the South Sea pearl.

The South Sea pearl is a labour of love, spending two silent years within the host oyster – the Pinctada maxima (commonly known as the silver or gold lip) or the Pinctada margaritifera (commonly known as the black lip). The breathtaking gift that is finally delivered into our world is well worth the wait.

AUTORE’s critically acclaimed pearl classification guide, the AUTORE Five S’s™ was launched in 2007 and continues to play an important role as an educational tool to build confidence for consumers and retailers to buy, sell and wear South Sea pearls.

Rosario Autore developed the South Sea Cultured Pearl Classification Guide which has been recognised by the respected Gubelin Gem Laboratories. The guide considers the quality of a South Sea Pearl based on its Shine, Surface, Shade, Shape and Size, and provides an in-depth explanation to understand pearl classification.

The AUTORE Five S’s is a registered trademark of Autore Pearls Pty. Ltd.

To download the AUTORE Five S®’s please click here


As in all things, true beauty comes from within, so the virtue rated above all others in a South Sea pearl is its lustre and shine. Lustre is the result of light reflected from the pearl’s surface combined with its deep inner glow (iridescence).

South Sea pearls are made up of many fine layers of a crystal-like substance called nacre, comprising organic and inorganic materials secreted from within the living tissue of the oyster. The quality and thickness of nacre gives a pearl both its radiance and its deep glow. The combination of light reflecting on the pearl’s surface and light refracting between each layer of nacre within the pearl is what makes this gem unique.

Shine has the magic to minimise other imperfections and is considered the soul of the pearl.

There are five broad categories of lustre:

I Brilliant lustre: producing a mirror reflection

II Excellent lustre: producing a very clear reflection

III Good lustre: producing a good reflection

IV Average lustre: the reflection appears opaque

V Poor lustre: producing very little reflection

I. Brilliant lustre
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