Troy weight - the system of mass units routinely used for measurement of gold, precious metals, jewels and smoky gunpowder.
One troy pound consists of 12 troy ounces, instead of from 16 ounces as it is accepted at usual pound. Weight of troy ounce is equal 480 grain surpassing weight of usual ounce of equal 437,5 grains. Both systems use the same grain - precisely 0.06479891 grammes. And though the troy ounce is used till now for weighing of gold, silver and jewels, the troy pound is not used any more.
Before acceptance of metrical system, in various parts of Europe in many systems of scales troy weight was in use, including in Holland, Paris etc. Their significances varied from each other on some percentage items.
The unique system where now are widely used troy weight is British Imperial, and its American colleague. Nevertheless, British Empire has cancelled troy pound in 12 ounces in weight in 19 century, while it has been saved (though is seldom used) in the American system.
To the USA, troy weight is a part of Incorporated state standard units.
The British system of imperial measures and scales (also known as Imperial units) has been created in 1824.
Troy weight has been used for the first time in England in 1400th years, and is officially declared by a gold and silver unit of measure in 1527.
The Origin of system of troy weight is not known. In due course was considered that it has originated in Champagne at fairs in Troyes, in the northeast of France. The English system of troy weight, apparently occurs from almost identical system of troy weight of Bremen which in turn, probably, has been based on very similar system of troy weight of Hamburg. There were assumptions of possible communication with medieval Norwegian skalpund (only 16 troy ounces), but only with indirect demonstrations. The name "Troy", probably, has been received from an ancient city of Troy, in error about a place of an origin of all system.