Most people buying pearl jewellery are not gemologists, and they should not need to be. But there are a few things worth knowing before you spend a significant amount of money on a piece. Some of them are visible to the naked eye. Others require asking the right questions of whoever is selling.

Lustre is the most important thing

Lustre is the quality of light reflection from the surface of the pearl. A high-lustre pearl looks almost like a small mirror: you can see a clear, sharp reflection of a light source or of your own face. A low-lustre pearl looks chalky or milky. Lustre is determined primarily by nacre thickness and density. It is the single most important indicator of quality, and it is visible in good light without any equipment.

Ask about nacre thickness

Nacre thickness matters because thin nacre chips, peels, and loses lustre faster than thick nacre. For Akoya pearls, a nacre thickness of 0.4mm or more is generally considered good. Some lower-quality Akoya pearls have nacre as thin as 0.1mm, which looks fine initially but deteriorates quickly. A reputable seller should be able to tell you the nacre grade of the pearls they are selling. If they cannot, that is worth noting.

Matching in a strand

For a strand, the pearls should be matched in diameter, shape, colour, and overtone. Small variations are natural and acceptable; large variations suggest the strand was assembled from mismatched lots. Look at the strand in natural light, not just under a jeweller's lamp. Overtone differences that are invisible under artificial light can be quite noticeable in daylight.

The clasp and cord

A pearl strand is only as good as its cord and clasp. Ask whether the cord is natural silk or synthetic. Silk is traditional and appropriate; some synthetic cords are fine, but they should be disclosed. Ask whether the clasp is solid gold, gold-filled, or plated. A plated clasp on an expensive strand is a mismatch that will show in a few years. The clasp should close securely and open without excessive force.

Surface quality

Pearls are organic and almost all of them have some surface characteristics: small bumps, ridges, or spots. A completely clean surface is rare and commands a premium. Minor surface characteristics are acceptable and do not affect durability. What to avoid: deep pits, cracks in the nacre, or chips near the drill hole. These are structural issues, not cosmetic ones.

If you have questions about a specific piece, whether from us or from another seller, you are welcome to email hello@drimanopearl.com. We will give you an honest answer.