How do you figure out what 20 grams 99.99 gold is worth compaired to a 1 ounce bar?. I just got 2 10 gram bars with assay cards?
But a metric ounce is different than a troy ounce. Metric ounces are roughly 28 grams and troy ounces are roughly 31 grams.
When I was a schoolboy in the '30s, avoirdupois ounces (16 to the pound) were 437.5 grains and used to measure the weight of all common objects troy ounces (12 to the pound) were 480 grains and used to measure the weight of precious metals; and grams (1,000 to the kilogram) were part of the completely separate Metric System in which the unit "grain" did not exist. When did that change, and how does a metric ounce compare to an avoirdupois ounce?
I believe the metric and avoirdupois ounce are the same because it takes 16 metric ounces to a pound.
Sorry my friend, the metric system and the English system are unrelated. "Metric ounces" are in the same league with Unicorns.
I understand that the metric and English systems are completly different. All I know is that there are 28.349 grams to an ounce, which is of course 1/16 of a pound.
IIRC, the change was in 1959. It was not a change that created a metric ounce. As you say, that doesn't exist. It was change that recognized that each country had a different troy ounce. Each country had a hunk of metal that represented a troy pound, which had been copied, as accurately as technology permitted at the time, from some other country's troy pound. Mid-20th-century technology, which was accurate to microgrammes, showed them all to be very slightly different. Most countries agreed to piggyback on the work that was being done to define the kilogramme precisely, and to redefine their troy ounce as 31.1034768 grammes. This made no significant difference to precious metals trading (at the time, a microgramme of gold cost about a nine-thousandth of a cent) and saved arguments. This means that 20g is closer to 0.643015 troy ounces. Later, John
