Lao Fengxiang's silver jewelry must be marked because the foot silver symbol is a mandatory symbol of the state.

Lao Fengxiang is just a company, and its trademark is a merchant, not a supplier of raw materials for jewelry. The foot silver logo is required by the state, so it will definitely be marked on jewelry. State regulations on these precious metal products.

Generally, the manufacturer's code, material name and content stamp are required to be marked. As a merchant of silver jewelry, Lao Fengxiang is not a manufacturer of silver products, so he can't mark the jewelry. If he marks it, he will cheat consumers.

Introduction to Foot silver

Foot silver is a Chinese word, which means silver with perfect color. According to international standards, foot silver refers to silver with a silver content of not less than 99, which is generally processed into bracelets, pendants, longevity locks and other silver ornaments. Foot silver ornaments usually have several symbols, one is S99, the other is S99, and S is the first letter of the English word Silver, which stands for silver.

silver is of great significance in the manufacture of photographic photosensitive materials, because the photosensitive agents coated on photographic paper and film are all silver compounds, such as silver chloride or silver bromide. These silver compounds are very sensitive to light, and when they are exposed to light, they decompose immediately, much in places with strong light, and little in soil fertility with weak light.

However, at this time, the image is only faintly visible. It must be developed to make it clear and stable. After development, it is fixed to remove the unexposed excess silver chloride or silver bromide from the negative. Contrary to the real scene, the image on the negative is called negative-where the light is strong, silver chloride or silver bromide is much decomposed.

The black thing on the black negative is very fine metallic silver, but the place with weak light appears whiter. When printing a photo, the black and white of the photo is opposite to that of the negative, so it is consistent with the tone of the real scene. Modern photography technology has been able to take a very clear photo in a few tenths to a few hundredths of a second under the weak match light.

Today, the world's silver used for film and photography has reached 15 tons every year.