Valuing an inherited necklace for probate is one of the things executors find hardest, because it looks as though it should be worth something and there is no obvious way to tell how much.

Natural pearl necklaces are extraordinarily rare and extraordinarily valuable, and if everything else in the jewellery box is modest, the odds these are the exception are very long. Almost everyone who inherits a string of pearls believes them to be natural. Almost nobody’s are (sorry).

The realistic question for an executor is not whether these are worth a fortune but whether they are cultured, simulated, or genuinely worth a proper look, and you can get most of the way to that answer just by handling them carefully.

What follows is how we assess a strand in practice, in the order you would check it yourself.

Look at the Beads Before You Do Anything Else

First of all pick up the necklace and actually examine the beads, because the single most common mistake is not looking. A simulated pearl is paint on a plastic bead, and that coating nearly always shows wear. Turn each one slowly in your hands and watch the surface. If you can see a coating lifting or flaking away with plastic underneath, your question is answered: these are imitation, not pearls at all. People skip this step because the necklace looks convincing at arm’s length, so they assume value that isn’t there.

Then slide the pearls along the string and look towards the drill holes. On simulated strands the plastic bead is sometimes visible at the hole where the coating hasn’t reached. You won’t always see it, but it shows up often enough to be worth the few seconds it takes. These two checks, the surface and the drill hole, will settle a surprising number of cases before you go any further.

Knotting Is a Clue, Not Proof

A knot tied between each pearl is a positive sign but it settles nothing on its own, which is where most amateur guides go wrong. The logic sounds good: knots stop pearls scattering if the string breaks, so a knotted strand must be worth protecting. The problem is that natural pearls are often small, and knotting between small pearls looks clumsy and chunky, so it simply isn’t always done. A strand can be knotted and cheap, or unknotted and fine. Treat knotting as one indicator among several, never the deciding one.

Perfect Matching Points to Culturing, Not Quality

Flawless uniformity of size and colour across a whole strand is a sign of a controlled production process. This goes against most peoples instincts because a perfectly matched row of identical pearls looks like the more impressive object but it is the opposite of what nature produces.

Natural pearls vary in size and shape, which is exactly why genuine natural strands tend to be graduated, larger in the centre and tapering towards the clasp, since finding many pearls of identical size, proportion and shape is very hard. If every pearl on the string is, say, six millimetres across with a colour match that is absolutely perfect, that consistency comes from cultivation. It is the hallmark of a manufactured or cultured strand.

A Plain Clasp Doesn’t Mean Plain Pearls

A simple clasp tells you nothing about the pearls it holds. Where the pearls themselves carry the value, they can sit on a very plain fitting, so the absence of anything showy at the clasp proves nothing either way.

Diamond-set clasps are common on good strands, but a strand of real worth can just as easily close on a modest gold catch. Do not write a necklace up or down on the clasp alone.

What About the Tooth Test?

Real pearls, both natural and cultured, feel gritty when rubbed gently against the teeth, while a smooth glassy bead does not, but treat this as a footnote rather than a method. We would not lean on it. Putting inherited jewellery in your mouth is unhygienic, not everyone can detect the grittiness in the first place, and dentures defeat it entirely. If you happen to try it and feel nothing, that alone should not decide anything.

What Pearls Are Actually Worth

The likely answer, on the balance of probability, is a good set of cultured pearls worth a few hundred pounds rather than the thousands most families expect.

Mikimoto is the benchmark at the top of the cultured market, and it makes the point cleanly. A new Mikimoto Akoya strand retails in the region of several thousand pounds; the UK site currently lists cultured Akoya pieces from a few hundred up to around eighteen thousand pounds for diamond-set designs, with a plain strand well within that range. Resale of an inherited strand, by contrast, lands in the mid-hundreds. That gap between retail and resale is the whole article in one figure, and it is not a fault in the pearls, it is simply what a used strand fetches when sold.

Majorica sits in a different category again, and it catches families out constantly. Buyers pick them up on holiday in Spain, keep them as an heirloom, and pass them down believed to be natural. They are neither natural nor cultured. Majorica, spelled with an “i”, is a Spanish maker of simulated pearls, described in Gems & Gemology as the most meticulously manufactured imitation pearl of its day, built on a glass core coated with a fish-scale essence. They are beautifully made and have almost no resale value, and the coating wears with age like any other simulant.

Genuine natural pearl strands do exist and they run into thousands and upwards, with exceptional examples reaching far higher, but they are genuinely rare and you should not assume a modest jewellery box holds one. What matters for the estate is the open market value: the price the pearls would reasonably fetch if sold on the open market at the date of death, not the price that was paid for them. That is the test set out in section 160 of the Inheritance Tax Act 1984, and HMRC’s own manual confirms it, defining the figure for inheritance tax as the open market value under s.160. Retail price is not that figure. Resale is much closer to it.

If You’d Rather Not Guess

Being told your pearls are worth a few hundred pounds rather than a few thousand is a lower figure on the estate’s tax bill, not a loss to you.

The value that goes on the form is what the pearls would sell for now, and an honest, lower figure is money the estate keeps rather than money gone.

None of the checks here replaces having a strand looked at properly, and with pearls the margin between simulated, cultured and natural is exactly where a trained eye earns its place. If you would rather not weigh it up alone, we value pearls and other pieces on the s.160 open market basis and say so on the face of the report, which is what HMRC looks for. When you are ready, see our jewellery valuation service and we will take it from there.