Silver is a beautiful precious metal and the most mysterious; it is called the lunar metal in the same way as gold is the solar one. Not only jewelry is often made of silver, but also talismans, amulets, utensils for rituals. This metal has many properties, one of them is blackening, which can occur suddenly and not necessarily with the participation of a person.
Instructions
Step 1
Often, the owners of silver rank this attack as a negative influence of evil forces. It is believed that unexpected blackening of jewelry is associated with damage or disorder in the body. And although this superstitious fear is not so unfounded, there is still a more mundane explanation for this circumstance, namely from the point of view of the laws of chemistry.
Step 2
Darkening of silver causes oxidation of this metal when it interacts with sulfur. This chemical reaction produces sulfides, which are gray-black chemicals that coat jewelry and other silver items.
Step 3
Sulfur can get on the product from human sweat, water, cosmetics and even air. This explains the fact that even objects that are practically not touched, for example, decorative ones, can darken.
Step 4
Silverware, as a rule, contains not only this metal, but also copper. This is due to the fact that silver is very soft and easy to deform, and the addition of copper makes objects more durable. Copper also oxidizes and causes sulfides to form even more, which in turn leads to darkening and silver.
Step 5
It is known that from jewelry earrings are less susceptible to darkening. This is due to the absence of sweat glands in the earlobes. Most often, chains and pendants darken, less often - rings, however, they can darken not due to sweat, but from contact with various chemicals, for example, when cooking or washing dishes, cleaning the house.
Step 6
The oxidation state of silver depends on the sample of the metal: a product of 999 (high) standard is less susceptible to darkening, more than 875. Cutlery, as a rule, contains more copper, therefore oxidizes more strongly and can almost completely turn black, so they require systematic maintenance.
Step 7
Human sweat can not only cause blackening of silver, but also, conversely, be the cause of its lightening. Religious people associate this with the light aura of a person, but there is also a scientific explanation for this: in addition to sulfur, sweat contains nitrogen, a large content of which reacts with silver and causes the decoration to lighten.
