A Guide to Pearl Grading

THE 5 PEARL VIRTUES

Discover the timeless elegance of pearls through our comprehensive grading guide.

Each pearl is evaluated on Size, Shape, Complexion, Surface spotting, Lustre and Colour. Each of these elements is carefully assessed and considered together, rather than in isolation. When combined, they are measured against a grading scale to determine the pearl’s final overall grade.

There is no universal grading system for pearls, as natural variations make each pearl unique. However, our grading system has been trusted by customers for over 30 years, giving strong confidence in the consistency, integrity, and reliability of our grading system.

Understanding these virtues helps you appreciate the natural beauty and value of these oceanic treasures.

Size

Pearls are initially sieved and recorded by mm after harvest. In the case of single pearl lots, the pearl is measured and recorded using a pearl gauge to the nearest tenth of a mm, e.g. 10.3mm. The pearl is measured across its widest point, i.e. diameter.

8mm

SMALL

Delicate and refined, perfect for subtle elegance

12mm

COMMON

Classic size, versatile for everyday wear

18mm

LARGE

Statement piece with impressive presence

20mm+

PREMIUM

Exceptionally rare, ultimate luxury

Shapes

Pearls are rarely identical and the shapes of pearls, aside from those that are round or very near to round, vary greatly.

Round

Defined by its near-perfect spherical shape, a well-formed pearl shows minimal variation and rolls smoothly with quiet precision.

Semi Round

Defined by its near-round form, subtle variations give the pearl its natural character.

High Button

Almost round in appearance, with a soft variation on one side. A slight wobble may occur when rolled, though it appears smooth and balanced when set.

Flat Button

Round in appearance from above, with a flat base and a wider, button-like form. Smooth, balanced, and naturally varied.

Drop

Tapered at one end with rounded sides and a smooth, symmetrical form. The opposite end remains softly rounded, creating an elegant elongated shape.

Short Drop

A softly rounded, fuller drop shape with a slightly wider base. Smooth along the sides, it appears almost round when worn.

Oval

An elongated oval shape with a smooth, symmetrical form and balanced proportions.

Necklace

A composition of pearl shapes that may range from round and uniform to more elongated, drop-like forms, often balanced together to create a naturally harmonious and refined strand.

Keshi

Smaller in size with naturally unique shapes, Keshi pearls are known for their exceptional lustre and soft, satin-like glow.

Baroque

Irregular and naturally formed, baroque pearls feature unique shapes and organic details, making every pearl one of a kind.

Circle

Defined by soft concentric rings that circle the pearl, appearing lightly or across the entire surface.

Colour

South Sea pearls from the Pinctada maxima oyster reveal a spectrum of colour, from luminous whites and silvers to warmer tones of cream, yellow, and gold. When observed in soft natural light against a white background, their nuances are best appreciated through a considered, side-by-side comparison.

White

Silver Mix

Cream

Yellow

Light Gold

Gold

Fancy

Lustre

Lustre reflects the interplay of light within the pearl, creating a soft inner glow and natural iridescence.

Excellent

Exceptional mirror-like reflection with sharp, bright surface

Medium

Good reflection with visible light play across the surface

Normal

Soft, diffused reflection with subtle surface glow

Complexion

Complexion refers to the surface quality of a pearl, where a smoother finish enhances its overall beauty and refinement.

Spot

The most common blemish, is a small, shallow depression, indent or sunken area on the pearl

Bump

A blemish resembling a raised scar, bruise or blister. Bumps may be uneven and discoloured (oftenappearing blue). The Japanese refer to this as ‘Shimi.’

Chip

An area of the pearl that appears to have been chipped or cut off.

Scratch

A blemish that resembles a score mark or scratch in a pearl’s surface.

Wrinkle

Small creases or crinkles in a pearl’s surface giving the pearl an orange peel effect. The Japanese refer tothis as ‘shiwa’ (hammering/shark skin).

Grading Letter

Pearl quality is evaluated through a combination of the characteristics outlined above. Together, these factors determine a pearl's overall grade. The most highly prized pearls are typically round white pearls with exceptional lustre and a flawless surface, free from visible blemishes.

A - Exceptional

Minor imperfections, good lustre, attractive appearance.

B - Excellent