A single stone is one diamond with its own weight, grade and usually a certificate. A parcel is many small stones kept and sold together, described by the number of pieces, the total carats and an average price per carat. Parcels are bought, sold and moved by pieces and carats, and their cost follows the carats that leave.
What is a diamond parcel?
Small stones — melee and smalls — are not handled one by one. They are sorted into parcels of similar size, colour and clarity and kept in a paper packet, with the pieces and total weight written on it: for example 120 pieces, 6.00 ct, G-H colour, SI clarity, 1.2–1.3 mm.
A single stone, by contrast, is one diamond large enough to be weighed, graded and usually certified on its own. It is bought and sold whole.
How is a parcel priced?
By the carat. A parcel has one price per carat for the whole packet, and the value is that price times the total carats. Because the stones in it are similar, the same price per carat applies to any part of it.
Example: 120 pieces, 6.00 ct at $400 a carat is a $2,400 parcel. The average stone is 0.05 ct (6.00 ÷ 120) — a figure buyers often ask for, because it says which size the parcel really is.
What happens when only part of a parcel is sold?
The buyer takes some pieces and some carats, and both come off the parcel. If 40 pieces weighing 2.10 ct are sold from the parcel above, 80 pieces and 3.90 ct remain. The cost that leaves is the carats sold at the parcel’s cost per carat: 2.10 × $400 = $840, leaving $1,560 of cost in the packet.
Pieces and carats must both be recorded. Pieces alone hide that the stones taken were bigger or smaller than average; carats alone hide how many stones physically left the packet.
What is a packet transfer?
Dealers often re-sort: some stones from one parcel are moved into another — to make a parcel more even, or to combine two lots of the same quality. The pieces and carats move, and so does their cost: the receiving packet takes the moved carats at the cost they carried, and its average price per carat changes to match.
When the two packets were bought in different currencies, the moved cost has to be converted at each packet’s own purchase rate — otherwise the receiving packet’s cost is wrong by the exchange rate.
Single stone or parcel — which way should a stone be kept?
- Keep it single when it has its own certificate, its own price, or will be sold on its own.
- Keep it in a parcel when stones are similar, small, and bought and sold by the carat.
- Split a stone out of a parcel when it turns out to be special — it then becomes its own item with its own price.
How Avirat keeps parcels
In Avirat every stone is either a single or a parcel. A parcel carries its pieces, carats and cost per carat; a sale, memo, return or transfer takes pieces and carats out, and the stock always shows what is left. A packet transfer moves stones between two packets in the same branch with their cost — converted when the packets were bought in different currencies — and a branch transfer can send part of a parcel to another branch as its own packet. A single stone can never be split or sold twice.
See how Avirat handles this: Diamond software