Buying melee in Mumbai: sieve sizes, parcels and the questions to ask
Small stones are bought by the parcel, not the piece. How sieve sizes, calibrated goods and screening work, and what to settle before the invoice.
Nobody buys melee the way they buy a centre stone. There is no report to read, no single stone to turn under a light, and no sensible way to grade four hundred diamonds one at a time. You are buying a population: a parcel described by size range, colour range, clarity range and make, and the skill in the purchase is knowing which of those four descriptions the seller has defined tightly and which one he has left comfortably vague.
That trade has a geography. The cutting happens in Surat, a few hours north, where the factories that polish most of the world's small diamonds sit beside the machines that do it. The selling, sorting and exporting happen in Mumbai. A buyer arriving from outside India often expects to meet cutters and instead meets exporters. Both conversations are useful; they are not the same one, and the person quoting you may be three steps from the wheel.
A parcel is a specification, not a pile
Small goods are sized by sieve rather than by weight, and the vocabulary is older than it looks. A plate with calibrated holes separates the stones that fall through from the stones that do not, and the resulting band is written as a plus size, so a parcel of plus one and a half to minus two is everything caught by one plate and passed by the next. Above that you move into stones-per-carat language: goods described as sixty to the carat, which gives you the average weight of a stone without promising any individual one.
Calibrated goods and the millimetre
Setting work changes the question. A channel, a pavé row or a halo needs stones that fit a seat cut to a figure, so calibrated goods are specified in millimetres with a tolerance rather than in sieve bands. Ask for that tolerance in writing, because five hundredths of a millimetre either way is a different product from two, and the second one costs more because somebody sorted for it. Ask too about matching: a row of stones each within tolerance can still step visibly in diameter from one end of a band to the other.
Make is where cheap melee turns expensive
Two parcels of the same size, colour and clarity can light up completely differently, and the difference is the cut. Single cuts and Swiss cuts carry fewer facets than a full cut and read as flatter in a row, which is right for an antique-style piece and wrong for a modern pavé. Beyond the faceting pattern, look for thick girdles, open culets, windowed stones and the unevenness that comes from goods polished to a weight target rather than a shape. Poor make is not paid for at the invoice. It is paid at your bench, in setting time and in breakage.
Screening, and the question you ask out loud
Melee is the part of the market where laboratory-grown stones and simulants travel without being announced, sometimes dishonestly and sometimes because a parcel was blended three owners ago and nobody re-tested it. Natural melee cannot be sorted by eye at these sizes, which is why the screening instruments exist and why reputable sellers expect to be asked. Ask whether the parcel has been machine screened, by what, and whether that can go on the invoice rather than stay a verbal reassurance. Then screen a sample yourself, because an undertaking is a remedy and an instrument is a fact.
- Sieve range or millimetre size with the tolerance, stated as numbers rather than a trade name
- Colour range and clarity range for the parcel, and what proportion sits at the bottom of each
- Cut: full cut, single cut or Swiss cut, and whether the make is consistent through the lot
- Country of cutting, and whether the goods were polished in-house or bought in
- Screening: what instrument, whether every stone or a sample, and whether it appears on the invoice
- Price basis: per carat or per stone, and the exact carat weight the invoice will use
- Fluorescence, which is invisible in one stone and obvious across a pavé row
- Rejection terms: what you may send back, within how long, and whether it is replaced or credited
You are not buying a diamond. You are buying the consistency of four hundred of them.
Settle the commercial terms with the same patience. Confirm whether the quote is per carat or per piece, because the two converge and diverge as sizes change and a verbal price with no unit attached is the origin of most melee disputes. Agree a weighing and agree who witnesses it. Ask what happens when a parcel arrives light, how a replacement is sized, and whether the goods leave on memo or as an outright purchase. If they are being exported to you, ask early who carries the clearance, since small goods cross a border as one lot under one description.
Valumira's eleventh show runs 10 to 12 September 2027 at the Bombay Exhibition Centre in the NSE Complex, Goregaon East, with manufacturing, polished diamonds and bridal gold as its focus, deliberately ahead of the festive season. Friday is trade only; Saturday and Sunday are open to the public. Bring your setting sizes, your tolerances and a note of what your bench actually rejects, because a parcel is only cheap if your own workshop agrees.