s very little frequents to find an object of gold damaged by the corrosion. The most appropriate cleanliness, generally, is with water and a soft detergent. If the dirt persists the fact is that it is not a pure gold and the treatment must be reinforced with little ammonia.

It is the most noble metal: 24 carats: pure gold 22 carats: 91,70 prayed; 4,20 silver; 4,10 charges. 18 carats: 75 prayed; 12,50 silver; 4,10 charges. 9 carats: 37,50 prayed; 31,25 silver; 31, 25 charges.

Silver

After the gold it is the most valued metal. To know the silver procentaje that has an object there is applied in a place slightly visible uba droplet of nitric acid. If the object has a suppressed silver high place the spot will be of beige / gray color. On the contrary, if it contains little a dark gray color will appear. Later it is necessary to wash well the object under the faucet with abundant water to eliminate the effects of the acid. For the cleanliness of the silver there exist very much commercial products that act correctly. If it is necessary to store a silver piece it is recommended to become accompanied by sachets of cloth that contain silica gel.

Bronze

The bronze is a copper alloy with tin. At present the sculptors use generally the following composition:

75 % charges 20 % zinc 2 % lead

The chromatic scale of tonalities changes from a clear gold to a dark brown. As for the cleanliness for the bronze there exists a special product that rubs with a clean cotton, clears up with water and dries off very well. It is necessary to bear in mind that the moisture can produce easily damages in the bronze.

Copper

The cleanliness of the copper is carried out by water and a detergent that is not abrasive. The spots verdeazuladas are eliminated by alcohol. With the vinegar it is necessary to be very careful, because it attacks to the copper. If the object has lime spots, these can be eliminated adding 15 % of calgón to the distilled water.

Iron

The iron is a metal very sensitive to the moisture. As protection measurement, the iron objects must wash its good, dry off and apply a protective vaseline layer to them.

Brass

The brass is an alloy of copper and zinc and it is much used to make decorative objects. His cleanliness is carried out dampening a cotton with water and ammonia. To know if an object is of brass