How a Gem Hunter Works: Private Gemstone Sourcing Explained

People imagine a gem hunter walking out of a jungle with a stone in his fist. Some days look like that. Most of the work happens before the journey and after it, at a desk in Bangkok, saying no. A private gemstone sourcing service is not a shop with a longer supply chain. It is a sequence of decisions made on one client’s behalf, and the order of those decisions is what separates a hunt from a purchase.

The mandate comes first

Nothing starts without a written brief. I call it the mandate because that is what it is: authority to buy one stone, within one set of limits, on your behalf. Species. Origin, if origin matters to you and it usually should. Weight, as a range rather than a number. Colour, described against something real, because “deep red” means five different stones to five different people and a master stone means one. Treatment, which in my office is never negotiable: unheated corundum, and emerald only at insignificant or minor oil. Purpose, because a stone that will be worn is judged differently from one that will be held. And a budget band, because the band decides which markets I walk into.

A good mandate is narrow enough to be found and wide enough to exist. Most of my first conversation with a client is spent moving the brief toward that line. A five-carat unheated pigeon’s blood ruby with no silk and a Swiss report at the price of a car is not narrow. It is fictional. I say so on the first call, not the tenth.

At origin, in daylight

The mandate decides the map. Ruby means Mogok and, increasingly, Montepuez. Sapphire means Ratnapura, Ilakaka, and the old parcels of Kashmir that surface in Bangkok and Geneva. Spinel means Mahenge and Luc Yen. Tsavorite means Merelani and Tsavo. Emerald means Muzo and Kafubu. I go to where the stone is traded closest to the ground, because every hand a parcel passes through adds a margin and subtracts a truth.

At the table the work is physical and repetitive. Parcels open, stones go on white paper, and I look at each one in the light I brought with me, never the seller’s. A daylight torch at 5500 K and a row of master stones settle most arguments in four seconds. I have written about judging colour when the seller controls the lamp; the short version is that I do not judge in it. A stone that needs a warm bulb to look right has told me what it is.

Most parcels close again. On a normal buying day I might handle a few hundred stones and buy none. That is not failure. That is the service. The client is paying for the stones I did not bring back as much as the one I did.

The laboratory decides, not me

When a stone meets the brief in my light, I buy it and I stop believing my own eyes. It goes to an independent laboratory, usually in Switzerland, sometimes to two when the origin is doing serious work in the price. The report has to say three things in the right order: what the stone is, what has been done to it, and where it likely formed. I have set out how to read that paper elsewhere. Here the point is simpler. Until the laboratory has spoken, the stone is mine and the risk is mine. The client does not pay for a hope.

Some stones fail here. A ruby that looked untouched on the tray comes back with evidence of low-temperature heating. A sapphire carries a treatment nobody disclosed. Those stones do not become someone else’s problem in my office; they go back into the trade at what they are actually worth, and the hunt continues. This is the step that a retail purchase skips and the step that makes the paper worth something later.

Cutting for light, not weight

Many fine stones arrive from origin in a native cut: deep, windowed, off-centre, because the cutter at source is paid by the carat he returns. Whether to recut is arithmetic, and I do it with the client. Sometimes a fifth of the weight leaves and the stone moves up a price band because the colour now holds through the tilt. Sometimes the stone is right as it is and the arithmetic says leave it alone. The cost of recutting is a subject on its own; the principle is that weight is what a cutter is paid for and light is what a stone is worth, and I cut for light.

If the stone is to be set, the setting is directed from Bangkok to a brief as tight as the hunt: metal, seat, the exact angle at which the crown meets a lit room. The stone is never handed to a workshop with a free hand.

Delivery, and the file that stays open

The client receives the stone with its report, the parcel paper it came in, the photographs, and a private record that continues after delivery: valuations, resetting, re-certification, and one day succession. Provenance is the one part of a stone that cannot be recut, so I write it down from the first morning. A serious buyer keeps that file whole for the rest of the stone’s life, and the next keeper inherits it.

What you are paying for

Not the airfare, though there is a lot of it. You are paying for a buyer who is on your side of the table and no one else’s, who carries his own light, who refuses more stones in a month than most dealers see in a year, who makes the laboratory prove the word before you pay for it, and who has no shelf of his own to move. Retail sells you what it has. A gem hunter looks for what you asked for, and tells you when it does not exist.

Most people buy the story. The few who buy the stone find their way to a desk like this one, and the first thing they receive is a form asking them to be precise.

Questions collectors ask

What does a gem hunter actually do?

A gem hunter sources a specific stone for a specific client: he takes a written mandate, travels to where that stone is mined and traded, judges parcels in daylight against master stones, buys the one that meets the brief, has it examined by an independent laboratory, has it cut for light rather than weight, and delivers it with its papers. The value is in the refusals: the hundreds of stones passed over so that one is right.

How long does a private gemstone search take?

Weeks for a well-defined mandate in a species that is trading, months for a narrow one, and occasionally more than a year for a stone that barely exists, such as a large unheated Burmese ruby of top colour or a Kashmir sapphire with clean paper. A hunter who promises a date is promising to lower his standard on that date.

Do you keep an inventory I can browse?

Almost none. Stones are bought against mandates, not for a shelf. Occasionally a stone is already in my hands and keyholders in the private archive see it before it is offered elsewhere, but the normal path is a mandate first and a stone second.