If you're looking to buy cultured pearl jewellery, "lustre" and "orient" are the two most important quality criteria.
Lustre: brilliance and depth
A high-lustre pearl reflects surrounding objects with almost mirror-like sharpness. Lustre depends on nacre thickness and crystallisation quality.
Orient: iridescent reflections
Orient is the iridescent colour that seems to come from inside the pearl. Slowly rotate a quality pearl under natural light — you'll see moving reflections of pink, green, blue, silver, purple.
Orient by species
Akoya: pink or silver orient. Tahitian: peacock green, aubergine, bronze. South Sea: soft golden or silver.
The five quality criteria
1. Lustre — the most important. 2. Surface — absence of blemishes. 3. Shape — roundness. 4. Size — larger = rarer. 5. Colour — natural or treated.
For your purchase
Prioritise lustre above all. A pearl with exceptional lustre and minor blemishes is worth more than a "clean" pearl with average lustre.