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Troy ounces, grams, and pennyweight: the units on the ticket
A troy ounce is heavier than you think if you grew up on grocery ounces. Pennyweight is jewelry talk. Ask which unit is on the scale.
If you mix up ounces, you will think the shop stole 10%.
They probably did not. You probably used the kitchen ounce.
Troy vs avoirdupois
Precious metal is troy.
- 1 troy ounce = 31.1035 grams
- 1 regular (avoirdupois) ounce = 28.35 grams
A “gold ounce” in this trade is troy unless somebody is being cute. Grocery scales are the other ounce. Do not weigh your eagles on the kitchen scale and then argue.
Grams
Jewelry tickets are often grams. Fine. 31.1 grams of 24k is about an ounce. 31.1 grams of 14k is not. Karat.
Pennyweight (dwt)
Old jewelry dialect. 20 pennyweight = 1 troy ounce. Some tickets still say dwt. Ask. It is not a trick if they tell you.
What to look at
The scale should be on zero with the empty tray (tare). The unit should be visible. If they convert in their head and will not show the raw weight, ask them to write the raw weight down. Testing in front of you.
Part of the coin shop counter wiki · visitors & collectors · NumisQ Learn