Measuring Gold Weight

Feathers, Gold, and Word Play, or is it?

The old riddle goes: what weighs more a pound of feathers or a pound of gold? Some say gold because it is heavier. Others say they are both a pound so they weigh the same. Both are wrong. How can this be? Tradition. Gold is not weighed in the ordinary weights. Gold is weighed in the troy measurement system. One ounce of gold is not the same as the ordinary ounce (really called avoirdupois ounce).

The best way to understand this is to convert them both to a uniform system. A gram or gramme is a standard metric unit of mass. An avoirdupois ounce converts to 28.34 grams approximately. The troy ounce is 31.1 approximately. You say, “Aha! Gold weigh more, so a pound of gold weighs more than a pound of feathers.” Unfortunately there is one more piece of the puzzle. We all know 16 ounces equal a pound. True in the avoirdupois system, but not in the troy. In the Troy system only 12 ounces equal a pound. So a pound of feathers weighs 453.59 grams approximately and a pound of gold weighs 373.24 approximately. So a pound of feathers weighs more then a pound of gold.

Some say gold because it is heavier. Others say they are both a pound so they weigh the same. Both are wrong.

There is more trivia about gold weights. The troy system historically was used for measuring the weight of drugs, precious metals and gemstones. The name comes from the French city of Troyes. The noble metals (gold, silver and platinum) all use the troy system. A troy ounce is 20 pennyweights. The pennyweight was the weight of a silver penny in medieval England. When pennies were introduced in England in the 8th century, their original weight is believed to have been 24 grains. This was gradually reduced, in at least thirteen stages until it reached 7.27 grains by 1816. 24 grains = 1 pennyweight and 20 pennyweights = 1 ounce troy.

Even more trivia if you’d like to read on. “Grain is an ancient unit which was originally based on the weight of a grain of wheat. The grain is the smallest unit of weight in the avoirdupois, troy, and apothecaries systems. Surprisingly it is identical in all three systems.” 4 grains = 1 carat; 24 grains =1 pennyweight; 480 grains = 1 troy ounce; 15.432 grains = 1 gram.

“Although we have stated above that the grain weighed the same in all three of the above systems, there were at least two different grains. The troy system used the supposed weight of the barley grain, whereas the wheat grain was also used as a standard of weight. There were three barley grains to four wheat grains.”

That is enough trivia for now. If you wanted to update the old riddle, you could say: what weighs more, a kilo of feathers or a kilo of gold?

What people are saying

  1. flankflank says:

    “The old pun goes” …. Um, pun?

  2. Shelly says:

    I have found a ring that I like. It is a ruff band but a good size. On the inside it has 14K a g. Does that mean it has silver mixed in the band?

    • Hi Shelly, thanks for asking. The “a g” portion of that stamp most likely refers to the manufacturer who made the ring. While it is true that silver is often included in 14k gold alloys (especially yellow and green gold mixtures), the stamp doesn’t usually make any reference to the non-gold alloys used.

  3. Donna Mosera says:

    Love your website.

  4. Jacqueline says:

    I have a question but not sure if this is the correct place to ask.

    My Mother Rita who sadly passed away almost two years ago gave me her engagement ring. I am aware it is amethyst and 24 karat gold, but it also has a small chip in it and a few scratches all on the stone. I am trying to find out if I can and how much this will cost me.

    The ring means everything to me, something to hold on to when breaking down in tears as we were so close. As you may gather, I do not wish to replace the stone I would just want it fixed. Do you have an idea how much this will cost me? Do you also know how much a ring fixed with 24 karat gold is worth at this moment.

    Kind Regards,
    Mrs Jacqueline Mirenda

    • Hi Jacqueline, thanks for commenting, and I’m sorry for your loss. We would be happy to help with your repair. It would be very unusual for a ring to be made out of 24 karat gold, so we would definitely want to see the piece before we could quote you any prices for it.

      Depending on how badly the stone is scratched/damaged, we may be able to have it repolished for you. If you are in the Sacramento area, feel free to bring the ring by, so we can look at it in person. If not, you can email us some pictures of it, and we can go from there. Here is our contact information.

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