To buy South Sea pearls well, judge them on five factors — lustre, surface, shape, colour and size — and buy from a farm-direct seller who discloses that the pearls are cultured Pinctada maxima and the colour natural. Lustre and honest disclosure should guide you more than any grade letter on a tag.

We have sorted thousands of these pearls, and the pattern among happy buyers is always the same: they knew which factor mattered most to them before they started looking. This guide gives you the factors, the questions worth asking any seller, and the simple daylight checks we use ourselves.

The five factors, in the order we weigh them

• Lustre: a deep, satiny glow with sharp reflections. This is the factor people see from across a room — weight it hardest.
• Surface: a few natural marks are normal on a pearl grown for years in the sea; cleaner skin grades higher.
• Shape: round is rarest and priciest; drops, ovals and baroques offer real beauty for less.
• Colour: bright white-silver and deep natural gold are most prized, and the colour is never dyed.
• Size: 9 to 16 mm, with price climbing steeply per millimetre — see our size and value guide for the full curve.

Questions to ask any seller

A seller who hesitates on any of these is telling you something. None of the questions is rude; every farm and dealer we respect answers them daily without blinking. Keep the answers in writing — an email is fine. Good sellers expect it; the rest will remember you asked.

Why farm-direct matters

Buying close to the source means fewer hands between the oyster and you. When we open a harvest, we can say which farm and which waters a pearl came from, and confirm the colour is the oyster's own. It also means patience in matching: instead of taking whatever a wholesaler has on the shelf, we can hold a strand open across seasons until every pearl agrees in tone and glow. That patience is invisible on an invoice, but you see it the moment a strand rolls across a table as one unbroken line of light.

Distance from the source is also where most pearl myths breed. By the time a strand has passed through four pairs of hands, "South Sea" can quietly mean "large freshwater", and "natural colour" can mean nobody asked. Fewer intermediaries means fewer places for the story to drift.

Reading a pearl in person

View pearls in daylight near a window, never only under shop spotlights. Turn them slowly: the lustre should follow the light with sharp, mobile reflections, and the colour should look alive rather than flat. Roll a strand gently to check the pearls graduate evenly and share one overtone, then hold them against your skin — the right pearl always looks a little better on you than on the tray. Trust that reaction; it is the oldest grading instrument there is. Photographs can do the same job if they are honest: ask for window light, no filters, and the same pearl from two angles.

Questions buyers ask us

Do I need a laboratory certificate?

It helps for major purchases, but for most buyers a trusted seller's written disclosure of culturing, origin and natural colour matters more than a letter grade. Certificates confirm; they do not replace your eyes. For pearls above 13 mm or a full strand, the paperwork is worth the modest fee.

Is a baroque South Sea pearl a lesser pearl?

Not at all — it is the same nacre and the same glow at a friendlier price, plus a shape no one else on earth owns. Baroques are how many collectors fall in love with the category.

Should I treat pearls as a financial asset?

No. Buy them to wear and pass down. The worth of a fine pearl lies in its quality and what it marks in your life, not in resale, and we will never tell you otherwise.

When you are ready to look, start with our loose South Sea pearls, each photographed in daylight, or begin smaller with South Sea pearl earrings. Send us your shortlist and we will tell you honestly which pearl we would choose, and why.