Your Weight in Gold
The idiom "worth its weight in gold" denotes something of immense value. Many commodities throughout history have been worth their equivalent weight in gold--salt, aluminum even black pepper.
Which Weighs More: A Pound of Gold or a Pound of Feathers?
Trick question? Not really. Gold and silver are measured in troy ounces. This system of measurement originated during the Middle Ages in the trading city of Troyes, France. The ancient system survives today as a measure of gold and other precious metals.
A troy pound consists of 12 troy ounces, each weighing 31.4 grams. The more familiar ounce (28.3 grams) is part of the avoirdupois system in which each pound consists of 16 ounces. Weighing each item according to its system, a pound of feathers is 21 percent heavier than a pound of gold.