For gold buyers & jewellers
A mixed-lot quote
someone can check.
A single total hides the assumptions. Keep each item’s weight, non-gold deduction, purity basis and price reference visible, then calculate the offer separately.
All prices and percentages below are fictional. US$100 per gram and an 80% offer are chosen only to make the arithmetic easy to follow. They are not live market data or a suggested buying rate. Purity is an assumption, not a verified test result.
Record the basis before the number
- Weight and unit: keep gross and deducted weight in the same unit. Do not mix ordinary ounces with troy ounces.
- Deduction: note assumed stone or other non-gold mass separately. A deduction is not proof that the remaining material is all the stated alloy.
- Purity basis: preserve the exact entered karat ratio or fineness. A hallmark alone does not verify authenticity.
- Price snapshot: save currency, price unit, source and the date/time you obtained it. Specify whether it is per gram of fine gold or already adjusted for an alloy.
This example uses a price per gram of fine gold and fineness values of 750/1000 and 585/1000. Do not apply the purity fraction a second time to a price already quoted per gram of that alloy.
The FTC explains karat as parts out of 24. A theoretical 14/24 ratio is about 0.583333, not exactly 0.585. If your input is 585 fineness, use 0.585 and retain that basis rather than silently changing it to 14/24. See FTC guidance on gold terminology.
Two items, one transparent estimate
Assume Item A weighs 10.000 g gross, with a 1.000 g non-gold deduction and 750 fineness. Item B weighs 5.000 g, with no deduction and 585 fineness. None of these assumptions has been verified by this worksheet.
| Item | Gross − deduction | Purity fraction | Fine gold | Melt estimate |
|---|---|---|---|---|
| A | 10.000 − 1.000 g | 0.750 | 6.750 g | US$675.00 |
| B | 5.000 − 0.000 g | 0.585 | 2.925 g | US$292.50 |
| Total | 14.000 g net alloy | Mixed; do not average blindly | 9.675 g | US$967.50 |
On a narrow screen, scroll the table sideways. Browser printing includes the worksheet.
Net alloy mass = gross mass − non-gold deduction
Fine-gold mass = net alloy mass × purity fraction
Melt estimate = fine-gold mass × reference price per fine-gold gram
Calculate each item at its own purity, then add fine-gold masses or values. A simple unweighted average of the two purities gives the wrong answer when their weights differ. Keep precision during the calculation and round the displayed monetary result at the end.
The melt estimate is not the offer
If, purely for this example, the buyer chooses 80% of the US$967.50 estimate:
Chosen offer = US$967.50 × 0.80 = US$774.00
The US$193.50 difference is not automatically profit. Refining charges, recovery losses, handling costs, price movements and other business costs may apply. A worksheet cannot determine a suitable commercial margin or guarantee any payout.
Use the same unit and currency for the reference and the quote. NIST’s precious-metals conversion information distinguishes the units used for precious metals. This example avoids conversion by using grams throughout.
Do not use a whole-item purity multiplier for gold-plated or gold-filled jewellery. A surface layer is not the same as a homogeneous gold alloy. The FTC distinguishes those constructions; this worksheet does not establish what an item is made of.
Keep the customer quote and internal worksheet distinct
- Identify each item and its gross weight, deducted weight and net assumed alloy weight.
- State the purity basis and whether it is assumed or independently tested. Do not label an assumption as an assay result.
- Show the reference price, currency, unit, source and snapshot time.
- Label the melt estimate separately from the actual offered amount.
- Record any expiry or conditions you actually agree; do not imply a guarantee that does not exist.
- Save a dated revision if an input changes. Preserve the earlier basis instead of overwriting the record without explanation.
A customer estimate should not accidentally include internal margin commentary or another customer’s details. Review any shared file before sending it.
Copy a quote checklist
Quote reference / revision: Recorded date and time: Reference price / currency / unit: Reference source and capture time: Item | Gross weight | Deduction | Purity basis | Fine-gold mass Assumptions or test references: Calculated melt estimate: Chosen offer / method: Agreed validity and conditions: Reason for revision: