First, by material to distinguish
Send gold coins (color coins, silver coins can not be sent) to the gold shop, put them on clean and smooth tiles (to prevent scratches), and burn them for 1 minute with high temperature. If it is pure gold material (including 91.6/% of early gold coins) ), unharmed, this is called real gold is not afraid of fire. If it is not pure gold material, it will be red and black. I tried it with a commemorative coin of 5 cents of copper coin /5 yuan. At a high temperature of 1000 degrees, after half a minute, the copper coin began to change color, and it could not be restored after discoloration. Use this method to eliminate 90% of fake gold coins.
Second, by weight to distinguish
Weighing, it is necessary for collectors to have an electronic scale and a caliper on hand. An electronic scale, 0.1 to 500 grams, can only be tens of dollars. The official weight of 1 ounce is 31.1035 grams. The error of gold coins below 1 ounce does not exceed 0.15 g/piece, and there is a problem beyond this error. If the weights match, you have to measure the size. In the official website of the China Gold Coin Corporation, there are detailed descriptions of the diameter of each coin, and the gold and silver coins after 2005 have color maps. You must always have an authoritative gold and silver coin catalogue to compare. If the diameter and thickness of the coin are consistent with the official website and the weight is also consistent, the coin is basically no problem. For the resolution of pure gold and silver high imitation coins, the above resolution conditions must be combined with the real money to be recognized. For example, distinguish the pure gold and silver high imitation of the Qinghai-Tibet Railway and the Olympic gold and silver.
Third, through the certificate to distinguish
The gold and silver coins issued by China Gold Coin Corporation have been printed on watermarked special banknotes since 2000. More than 90% of counterfeit goods are not printed on banknotes. The fake certificate generally prints the pattern of the watermark directly on the surface of the paper, while the true watermark is specially made inside the paper, and the two are easier to separate. The real certificate number is clear and natural, and the fake certificate number is hard and irregular. The fake certificate is basically a fake, and the true certificate may not be the real one. Please pay attention to the friends.
Fourth, through the authorized distributors of gold in various places to identify / or senior currency dealers . Find someone or a friend who is familiar with it to help you look at it. Sometimes it is worthwhile to spend some money.
2020 hot sale 50w 100w 150w cob grow light, waterproof IP67, use Epistar 50w cob flip chip, pink lighting/3500k white lighting for you to choose.
50w 1pcs cob chip, can replace hps 300w;
100w 2pcs cob chip, can replace hps 500w;
150w 3pcs cob chip, can replace hps 1000w.
Waterproof Best Cob Led Grow Light, is your best choose for indoor plants, each lamp with bracket, easily install.
50w:
100w:
150w:
Cob Led Chip,Best Cob Chip,Led Cob Chip Grow Light,Cob Chip On Board Technology
Shenzhen Wenyi Lighting Technology Co., Ltd , https://www.wenyigrow.com