Grading the Qualities of Pearls

The single most important thing to understand about pearl grading is that no industry-wide recognised standards exist. This means every grading system used by every company and pearl producer is unique and subjective. It is therefore impossible to compare grades and grading systems from one jeweller or producer to another.

The Gemological Institute of America (GIA) is widely recognised as the world’s foremost authority on pearls and it’s their Pearl Grading System that we use. In our view, it’s the most thorough and takes into account all the different factors that affect the quality and therefore value of a pearl.

The GIA’s 7 factors that determine the value of a pearl are: Size, Shape, Color, Nacre, Luster, Surface, and Matching.

Pearl Sizes

The size of the pearl has a direct bearing on its quality and price.

Larger pearls command higher prices (with all other factors being equal).

Pearl Shapes

The shape of the pearl is one important area where “value” and personal taste may diverge.

In general, round and near-round pearls are the most valuable, because of their rarity.

freshwater pearls

Pearl Colours

Pearl colour is another area where the most “valuable” pearl may or may not be the most appropriate pearl for you as an individual.

Pearl colours range across almost the entire spectrum from white to black.

Pearl Lustre

A pearl’s lustre is a measure of its brilliance and reflectivity.

The more lustrous the pearl, the more it shines and reflects light and images.

freshwater pearls
freshwater pearls

Pearl Surface

The appearance of the surface of the pearl is perhaps one of its most critical characteristics.

The surface should be smooth and clean, without bumps, spots, discolourations, or other disfiguring characteristics.

Pearl Nacre

Nacre is the substance from which the pearl is actually created.

The thickness of the nacre often determines how durable the pearl will be over time.

freshwater pearls
freshwater pearls

Pearl Matching

Pearl matching is the evaluation of the complete appearance of a pearl strand.

Matching can include size, colour and quality.