From the movie, they appear to be at least the size of a quarter. A solid gold coin 5 grams in weight should be less than the size of a penny. It seems unlikely that they’re 90% hollow, since gold is such a weak metal and they’d crush so easily.
It’s possible that in HPMoR they just made galleons a lot smaller to be portable. Otherwise you’d go shopping for a broom and need a giant sack of money with you instead of just a small pouch for your pocket.
From the movie, they appear to be at least the size of a quarter. A solid gold coin 5 grams in weight should be less than the size of a penny. It seems unlikely that they’re 90% hollow, since gold is such a weak metal and they’d crush so easily.
It’s possible that in HPMoR they just made galleons a lot smaller to be portable. Otherwise you’d go shopping for a broom and need a giant sack of money with you instead of just a small pouch for your pocket.