What is a gold foil bead?

2. Gold foil is a thin sheet hammered with gold. One or two (365,438+0.25 g) pure gold can be hammered into gold foil with a thickness of one tenth of a millimeter and an area of 65,438+06.2 square meters due to its good ductility and plasticity. That is, one gram of gold can be made into pure gold foil of about 0.5 square meters with a thickness of 0. 12um. The standard specification of gold foil is 9.33*9.33cm Other commonly used specifications are 8*8cm, 10.9* 10.9cm, 4.5* 1.5cm and 2.75*2.75cm.

Gold has the characteristics of stable nature, permanent discoloration, oxidation resistance, moisture resistance, corrosion resistance, mildew resistance, insect resistance and radiation resistance. Gold foil made of gold is widely used. In ancient times, the method of making gold foil was to purify gold, then beat it into gold leaves with an area of 2.5 square centimeters with a thousand hammers, then put it into black gold paper smoked with kerosene, and then beat it for 6-8 hours by hand to make the gold leaves into foil, about 40 times the area of the gold leaves, and then cut it into squares. Gold foil is a traditional handicraft of the Chinese nation, which originated in the Eastern Jin Dynasty, matured in the Southern Dynasties and was popular in Song, Qi, Liang and Chen Dynasties. Today, the Longtan area (Jiangning) in Nanjing is the birthplace of gold foil, which is said to have a history of nearly 1700 years. The inscription on the tomb of Cixi in Dongling, Beijing is a typical gold foil product.

The gold foil made by traditional technology takes gold bars with 99.99% gold content as the main raw material, and after more than ten special processes such as chemical cleaning, hammering and foil cutting, it is golden in color, bright and soft, as light as a feather, as thin as a cicada's wing and less than 0. 12 micron in thickness.

Step 3: Types

Gold foil is different from "red gold" and "gold" Since the late Qing Dynasty, there have been many titles such as "Ku Jin as foil", "Su Dazhi" and "Tian". The color of "Ku Jin Foil" is red, the fineness of gold is the best, and Zhang Zi is also the largest, about three inches square. "Sudachi" is yellow in color and poor in color. Zhang Zi is about two inches and eight minutes square. This light and white color is called "sky"

"Red gold", like gold in color, is actually smoked with silver, which is called "selected gold foil". The gold foil handicrafts unearthed in Sanxingdui and Jinsha in Sichuan are very representative, such as gold foil tiger, gold foil phoenix, gold foil frog ornaments and gold foil fish ornaments.

4. Distinguish whether the gold foil is real gold.

Generally, we can observe with the naked eye that real gold foil will appear green to light, while imitation gold foil will not appear green to light; Also, real gold foil is much thinner than imitation gold foil, which is easy to break when touched, while imitation gold foil is much thicker than real gold foil and will not break when touched. Also, real gold is not afraid of fire, and it can distinguish between true and false when burned. The main raw material of imitation gold foil is copper. Burning copper oxide will turn black, but real gold will not. If you want to measure the pure gold content of gold foil, you have to use a special instrument, but it can also be roughly distinguished by human eyes, including 9 red, 8 yellow and 7 blue. That is, those with a gold content of over 90 are light red, those with a gold content of 80 are light yellow, and those with a gold content of 70 are cyan.

Nowadays, the production of gold foil has been integrated into modern science and technology, and the auxiliary materials (such as Wujin paper) and equipment used have been greatly innovated, and the output and quality have been greatly improved. Modern science and technology will carry forward the traditional gold foil technology and develop new varieties of gold foil, such as high-tech laser shallow carving and bronzing on gold foil with purity of 99%, which has the value of preservation, collection, commemoration and appreciation.