Can you expand on this?
Also, the Troy weights are a measure of mass, I think, not actual weight, so if you went to the moon, an ounce of gold would be lighter than an ounce of feathers.
...gold having its own measurement system is really silly.
“avoirdupois” (437.5 grain). Both it and troy (480 grain) ounces are “normal” for different uses.
In this case, there's not enough context to tell, so the comment is total BS.
If they meant ounces (volume), then an ounce of gold would weigh more than an ounce of feathers, because gold is denser. If they meant ounces (weight), then an ounce of gold and an ounce of feathers weigh the same.
That's not really accurate and the rest of the comment shows it's meaningfully impacting your understanding of the problem. It's not that an ounce is one measure that covers volume and weight, it's that there are different measurements that have "ounce" in their name.
Avoirdupois ounce (oz) - A unit of mass in the Imperial and US customary systems, equal to 1/16 of a pound or approximately 28.3495 grams.
Troy ounce (oz t or ozt) - A unit of mass used for precious metals like gold and silver, equal to 1/12 of a troy pound or approximately 31.1035 grams.
Apothecaries' ounce (℥) - A unit of mass historically used in pharmacies, equal to 1/12 of an apothecaries' pound or approximately 31.1035 grams. It is the same as the troy ounce but used in a different context.
Fluid ounce (fl oz) - A unit of volume in the Imperial and US customary systems, used for measuring liquids. There are slight differences between the two systems:
a. Imperial fluid ounce - 1/20 of an Imperial pint or approximately 28.4131 milliliters.
b. US fluid ounce - 1/16 of a US pint or approximately 29.5735 milliliters.
An ounce of gold is heavier than an ounce of iridium, even though it's not as dense. This question isn't silly, this is actually a real problem. For example, you could be shipping some silver and think you can just sum the ounces and make sure you're under the weight limit. But the weight limit and silver are measured differently.
Using fluid oz for gold without saying so would be bonkers. Using Troy oz for gold without saying so is standard practice.
Edit: Doing this with a liquid vs. a solid would be a fun trick though.
