Run of Mine — Unsorted Production from Mine to Buyer
Run of Mine — Unsorted Production from Mine to Buyer
ROM parcels in diamond and coloured-stone trade, sold by weight or volume before sorting
Run of mine, abbreviated ROM, denotes unsorted and ungraded production taken directly from a mine and sold without intermediate processing or valuation. Run-of-mine parcels contain the full quality range that the deposit produces — gem, near-gem, and industrial material together — and the buyer pays a single price for the entire parcel by weight or by volume, accepting the responsibility of subsequent sorting, grading, and onward sale. The term is common in the diamond trade, where it has a long history in major-producer commercial relationships, and is used in parallel ways in the coloured-stone trade.
The diamond context
De Beers historically purchased run-of-mine production from contract producers under long-term agreements, sorting the combined production at the Central Selling Organisation (later the Diamond Trading Company) before distributing parcels to authorised sightholders. The ROM purchase model gave producers price certainty and gave De Beers exposure to the full output of each contract source, allowing the organisation to balance and blend stones across its sights. The model has evolved with the breakup of the historical De Beers monopoly, but ROM-style purchasing remains a feature of major producer-trader relationships.
Within the contemporary diamond trade, run-of-mine parcels move from producers to authorised buyers at central sorting facilities, where the parcels are broken into commercial categories by size, shape, colour, and clarity for onward sale. The economics of the model depend on the buyer's ability to extract higher value from the sorted goods than was paid for the unsorted parcel.
The coloured-stone context
In coloured stones, ROM purchasing is most common in larger-volume operations: ruby and sapphire production from Mozambique, Madagascar, and Mong Hsu; tourmaline from Mozambique and Brazil; aquamarine from Brazil and Pakistan. Producers and concession-holders sell unsorted parcels by the kilo or by the lot to dealers who specialise in sorting and onward distribution. Artisanal and small-scale operations often sell ROM-style as a matter of practical necessity, lacking the infrastructure for in-mine grading.
Buyers of coloured-stone ROM typically have established sorting capacity in cutting centres such as Bangkok, Jaipur, Idar-Oberstein, or Hong Kong, and the value extraction depends on technical skill in identifying gem material from the larger run of mixed-quality stones. The risk-and-reward profile is high: a parcel containing one or two exceptional stones can deliver disproportionate returns, while a parcel of largely industrial-grade material may barely cover purchase cost.
In the trade
For dealers, ROM purchasing requires capital, sorting expertise, and the ability to absorb individual parcel losses against a portfolio of expected average returns. The model is not appropriate for smaller dealers or for buyers seeking specific stones at known qualities. For producers, it offers cash flow and price certainty in exchange for the loss of upside that sorting and grading might otherwise capture. The ongoing tension between ROM and sorted-sale models has shaped both diamond and coloured-stone supply chains for over a century.