How try gold?
In age-old times when in the course there were gold coins to check their validity, took a bite of them. It was literally test - taste gold differed from taste of other metals markedly. Now with it it is easier - test of gold is, as a rule, specified on a product.
All know that the test, the better on quality the bought chachka is higher. But what is specifically meant by test, the people know vaguely.
And everything is very simple. Test shows the content of pure metal in an alloy. On gold products it is possible to see such tests - 333, 375, 500, 583, 585, 750, 900, 916, 950, 958. For example, gold about breakdown 585 means that 585 parts of gold are the share of 1000 parts of an alloy. The rest - copper, silver and some other metals. The purpose of such additives is increase of durability of a product and a variety of its color scale.
The most widespread tests of gold 583 and 585. Distinction extremely small, in fact, is the same structure, just the standard providing release of products 583 tests was replaced new on which began to let out test gold 585. It was made to combine alloy parameters with foreign standards. These alloys are considered the best on appearance and resistance to wear.
Abroad test is estimated in carats. The most high-standard product in such measurement corresponding to 100% of gold - 24 carats.
Before revolution test of gold was estimated in zolotniks. 100% of gold - 96 zolotniks.
The sign of test consists of number and any drawing. In our country till 1958 on products represented the worker`s head, and then a sickle and a hammer. Imperial Russia represented the female head in a kokoshnik.
But not always the specified test is true, especially it concerns products from foreign countries. There it is easily possible to get on a fake therefore buy jewelry only in solid expensive shops.
Probirovaniye history old. Began to be engaged in Probirovany in Ancient Egypt, improved it in Babylon, Greece. Famous Archimedes opened for all the law, trying to solve a problem of definition of test of gold in an imperial crown.
Now there is a lot of methods of check of gold alloys. One of them, simple and fast, though not the most exact, consists in a procherchivaniye the checked product on a surface of special abrasive whetstone of line 10 - 15 mm long.
Particles of metal of a product remain on a stone surface. Special gold needles of the known test near line from the checked product draw strokes.
Across strokes apply a reactant strip on a stone - nitric acid. Under the influence of acid alloy metal (except gold) is oxidized, line darkens. If color of line from a product is more dark, than color from an assay needle, then test of the examinee of a product is lower.
An assay stone - not a simple abrasive. It has to possess resistance to acids and other reactants. Should not contain impurity of connections, iron, copper and other non-ferrous metals. The stone has to be uniform and as less as possible porous. It is desirable that color was black that the strokes put on it were well visible.
For the first time such stone was open in Ancient Lydia. Now in our country use the stone found on the river Shunga in Karelia. It is called shungit. This stone is quite suitable for a probirovaniye. It is well polished, is black.
Before using an assay stone, it is oiled almond or nut and dry wiped the filtered paper. After each test the stone is smoothed out pumice, a small skin or abrasive powder as its surface has to be opaque.
We will hope that your jewelry quite corresponds to the test specified them.]