In Denmark and Greece, the legal minimum is 8 carats. In terms of weight, 1/20th of a pound or 0.05 oz is equal to 1 gram. So, 2 grams is half a ounce, 4 grams is an ounce, and so on. A single grain of sand is about.0078 inches thick. If you packed all the grains of sand into a ball, it would be about 1/8 of an inch thick. A sheet of paper has about 80,000 grains of sand per square inch. If you stacked these sheets of paper together, they would be about 1 inch thick. The average person's skull contains around 60 pounds of water. This is because much of our body weight comes from water (approximately 75%). The rest is made up of proteins and fats. Greek gold was probably first made into coins around 300 B.C. However, it wasn't until the late 19th century that gold coins were used extensively as currency in America. Today, gold coins are still used as currency by some countries around the world.