The scale
Buy a digital pocket scale that reads to 0.1 g with a capacity of at least 200 g. They are sold everywhere for the price of a takeaway meal and they are the same resolution a jeweller uses on small items. Anything that reads only to whole grams is not good enough, because at the current price a single gram of 14k gold is $77.52 and rounding it away on every piece adds up fast.
Most pocket scales ship with a calibration weight or expect a standard one, commonly 100 g. Run the calibration when it arrives and again if it has been knocked about. A scale that is out by a percent is worse than useless, because it gives you false confidence rather than no answer.
Weighing properly
Put the scale on a hard, level surface. Not a tablecloth, not a rug, not a wobbly table. Close the windows and switch off any fan: a draught will move the reading on anything light. Let the scale settle to zero before you put anything on it, and tare it if you are using a dish.
Weigh each karat separately. This is the single most valuable habit, because a buyer handed a mixed pile has every reason to price the whole thing at the lowest karat present. Sort into 10k, 14k, 18k and unmarked piles first, then weigh and record each one. Write the numbers down before you leave the house.
Weigh small items in a group rather than one at a time if they are the same karat. A scale is least accurate at the very bottom of its range, so three earrings together give a better reading than three separate ones, and the total is what you are selling anyway.
Stones, and what to take off
Remove anything that is not precious metal before weighing: leather cord, fabric, rubber, watch straps, steel spring bars, glued-in plastic. Do not attempt to pull stones out of settings. You will damage the stone, damage the mount and probably cut yourself, and a buyer who wants them out has the tools.
For a set piece, record the gross weight with stones and expect a deduction. A small accent diamond is a few hundredths of a gram. A large centre stone can be a gram or more. Ask the buyer to tell you the deduction in grams rather than as an unexplained reduction in the offer, and check it against the gross weight you measured at home.
Typical weights, as a sanity check
| Item | Typical weight |
|---|---|
| A thin wedding band | 2 to 3 g |
| A wide wedding band | 6 to 9 g |
| A solitaire engagement ring, metal only | 3 to 5 g |
| A 20 inch curb chain | 10 to 20 g |
| A fine box chain | 2 to 4 g |
| A pair of small hoops | 1 to 3 g |
| A class ring | 8 to 15 g |
| A charm bracelet with charms | 15 to 40 g |
If your reading is far outside these ranges, something is wrong: the scale is uncalibrated, the unit is set to pennyweights or ounces rather than grams, or the piece is hollow. Hollow chain and puffed hoops are common and weigh a fraction of what their size suggests, which is not a fault, just a fact to know before you get your hopes up.
Check the unit on the scale
Every pocket scale has a mode button that cycles g, oz, ozt, dwt and often ct. It is easy to knock it into the wrong one and not notice. A reading of 5 with the scale in pennyweights is 7.8 grams, and a reading of 5 in ounces is 141.7 grams, which is not a piece of jewellery at all. Glance at the unit indicator before you record anything, and set the calculator to the same unit. The units page covers what each one is.
Weighing questions
What scale do I need to weigh gold?
A digital scale that reads to 0.1 g. They cost very little and are sold as jewellery or pocket scales. A jeweller uses the same resolution for small items, so you are not at a disadvantage.
Can I use a kitchen scale?
Only for a large lot. Most kitchen scales step in 1 g or 5 g, which rounds a 5.4 g ring to 5 g and loses you money on every piece. They are also least accurate at the bottom of their range, which is exactly where jewellery sits.
How do I weigh gold without a scale?
You cannot do it accurately, and estimating by feel is how people arrive at expectations that the counter will not meet. Any jeweller or pawn shop will weigh a piece for you for nothing, and coins can be counted rather than weighed.
Should I weigh the stones with the metal?
Weigh the whole piece and note that it includes stones. A buyer will deduct an estimate for stone weight. Do not try to guess the deduction yourself: know the gross weight, and ask the buyer to state their deduction in grams.
Do I need to remove the clasp from a chain?
No. A gold clasp on a gold chain is the same metal at the same karat and is part of the weight. Remove only things that are not precious metal: leather, cord, rubber, steel spring bars in a watch.
How accurate does the weight need to be?
To 0.1 g. At current gold prices a tenth of a gram of 14k is worth a few dollars, so that resolution is enough for a fair conversation and finer resolution buys you nothing you can negotiate over.
Why does my weight not match the jeweller scale?
Usually calibration or a draught. Cheap scales drift and need their calibration weight run occasionally, and an open window will move a reading on a light item. If the difference is more than a couple of tenths on a small piece, calibrate and try again.