Grains are the smallest unit of weight used in precious metals, but that is not the only reason grains are used. Grains provide uniformity across multiple systems of measurement, facilitating streamlined trade and commerce.
What is the Weight of a Grain?
Since the implementation of the international yard and pound system in 1959, one grain has been equal to 64.79891 milligrams, and this weight is based on the ideal weight of one seed of grain.
One source states that 252.458 grains would balance a single cubic inch of distilled water. A more practical way of stating the weight of one grain would be that one grain is equal to 0.064 grams or that there are 15.625 grains in one gram.
Historical Weight of a Grain
Grains have been used as a measure of weight since the Bronze Age. They provided a relatively consistent measure across regions and cultures, which left them ingrained in weight systems, especially those used for precious metals.
Grains were the foundation of the pre-1527 English weight system, known as Tower weight, which based the unit on a grain of barley with about 133% the weight of one wheat grain. The grain was also the basis for a medieval English inch, which was defined as the length of three medium barleycorns lined up from end to end.
The English silver penny weighed 32 grains, and an older coin, the Sumerian shekel, was equal to the weight of 180 grains.
The traditional weight of one French grain was 53.115 milligrams.
How do Grains Provide Uniformity Across Measuring Systems?
The grain is the only unit of weight that is equal throughout the avoirdupois, troy, and apothecaries systems. There are 7,000 grains in an avoirdupois pound and 5,760 grains in a troy or apothecary pound.
Standardized systems streamline trade and commerce by ensuring that weights and measures are easily exchangeable and convertible. This provides an element of transparency and ensures that buyers and sellers are speaking the same language.
Why are Grains Still Used Today?
A system based on the weight of a grain seed may seem archaic, but it offers practical advantages where precision and granularity are necessary. This system has evolved and changed in small ways over the centuries and yet is still remarkably close to the ancient standard.
Grains are not only used in precious metals but in jewelry and firearm ammunition, as well. Grains offer jewelers the ability to make precise modifications to a design and ensure reliability in the weight of precious metals necessary to complete a design.
In jewelry and precious metals, the slightest difference in weight can account for a fluctuation in value and a fair market price. Weighing a valuable object like a ring or coin down to the grain ensures fair transactions and consistency in production.
The use of the grain as a measure of weight is essential today for standardization among different systems used across the world, like the Troy and Avoirdupois systems.
