Sourcing
How Professional Buyers Submit Gemstone Requirements
The difference between a requirement that gets filled in two days and one that takes three weeks is usually eight lines of specification.
6 min read
Most sourcing delays are not caused by scarcity. They are caused by a requirement that could describe forty different stones, which means the supplier guesses, sends the wrong thing, and both sides start again a week later.
A well-written requirement is not longer than a badly written one. It is just specific in the places that determine what gets pulled.
The eight fields that actually matter
- Species and variety
- "Sapphire" is a starting point; "teal sapphire" narrows it considerably. Where a trade term is loose — teal, rubellite, mandarin — send a reference image with it.
- Colour band, not a colour name
- Give a tone range and say what secondary colour you can live with. "Medium blue, slight grey acceptable, no green" is worth more than "royal blue".
- Size — carats or millimetres, and say which
- If the stone must fit an existing setting, specify millimetres. Two stones of identical face-up dimensions can differ by 20% in weight depending on depth, so a carat weight alone will not guarantee a fit.
- Depth limit
- The most commonly omitted field, and a frequent cause of a rejected parcel. If your mount has a depth ceiling, state it in the requirement rather than discovering it at the bench.
- Quantity, and whether it repeats
- A one-off hundred pieces and a hundred pieces every quarter are different commercial problems. A repeating programme carries a matching obligation across deliveries and is quoted differently.
- Quality floor or quality average
- For production, consistency matters more than the best stone in the parcel. Say whether you are buying to a floor — nothing below this — or to an average across the lot.
- Treatment tolerance
- "Heated acceptable" opens the market up enormously in corundum. "Unheated only, with report" is a different and much smaller market at a different price. Decide before you ask.
- Destination and timing
- The destination country affects documentation and despatch. A deadline affects whether a stone is sourced or substituted.
A requirement that works
Here is the whole thing, in the form a supplier can act on immediately:
- Sapphire, teal, medium tone, slight green acceptable
- Emerald cut, 5 × 3 mm calibrated, depth max 2.6 mm
- 100 pieces, repeating quarterly
- Eye clean at 10 inches, consistent across the lot
- Heated acceptable, no diffusion or filling
- Delivery to the United States, needed within six weeks
That is eight lines and it eliminates almost every round trip. Our requirement form walks through these fields in the same order, and you can attach a reference image at the end.
What not to bother specifying
Clarity grades borrowed from diamond do not transfer. There is no universally applied VS or SI scale in coloured stones, and asking for one produces confusion rather than precision. "Eye clean", "lightly included", "included but bright" are the terms the trade actually works with.
Origin, unless it genuinely matters to your customer. Origin determination requires a laboratory, adds cost and time, and narrows availability sharply. If it is a preference rather than a requirement, say so — it may cost you nothing to drop it.
An exact carat weight for a calibrated order. Specify the millimetre size and let the weight fall where the cut puts it.
Have a requirement?
Send the specification and we will come back with what matches.
