Author: Curry, Deep Tide TechFlow

The saying "real gold is not afraid of fire" has become less effective this year.

Yesterday, CCTV exposed a new method of gold fraud. A gold shop in Changxing County, Huzhou, Zhejiang took in a gold necklace last year, with the seller claiming it was made from gold bought previously. The shop owner followed the procedure to verify it, and there were no issues when visually inspected; the spray gun did not change color, and the weight matched. With gold prices over eight hundred per gram, the shop owner happily paid.

That afternoon, a seasoned craftsman in the shop felt something was off. He cut the necklace open to inspect the cross-section, finding the texture rough, which did not resemble the smooth, droplet-like cross-section of pure gold.

After reporting to the police, they traced the funds and discovered the gang's trading records spread across several provinces, with more than one gold shop being defrauded. In the end, two core members were caught in a gold processing workshop in Wuhu, Anhui. According to the Changxing police, the total value involved exceeded 800,000 yuan.

The workshop was equipped with high-temperature melting furnaces, molds, hammers, and a kind of silvery-white powder.

This powder is called rhenium, element number 75 in the periodic table. It has a feature that gives the entire gold industry a headache:

The density is almost the same as gold, but its melting point is three times that of gold. You can't burn it out. You can't weigh it out. When measuring with a spectrometer, according to Song Jiangzhen, director of the Southern Gold Market Research Center in Guangdong interviewed by CCTV, the atomic numbers of rhenium and gold are only 4 apart, resulting in highly overlapping signals on the instruments, causing standard gold testing devices to mistake rhenium for gold.

The gold industry's verification methods, used for thousands of years, have been penetrated by this metallic powder.

This issue is not just happening in Changxing. According to reports from CCTV and various local police announcements, from 2024 to now, cases involving rhenium-mixed gold have emerged in Xiangtan, Hunan, Hebi, Henan, Quanzhou, Fujian, Shanghai, Chongqing, and Ningbo, Zhejiang. The Quanzhou Gold and Jewelry Association has stated that they are receiving related complaints frequently, with methods becoming increasingly covert.

Gold is currently over one thousand per gram, while rhenium powder is priced at dozens of yuan per gram on e-commerce platforms. The price difference is obvious, and the testing cannot block it, so naturally, some people start brainstorming.

After all, there's always someone willing to counterfeit valuable trending items.

Rhenium powder, easy to produce yet difficult to verify

The threshold for this fraudulent business is much lower than imagined.

A recycling shop owner in Quanzhou, who has been in business for many years, told the media that previously rhenium was mixed in small particles, thus somewhat noticeable within gold ornaments. Now, rhenium powder is ground as fine as flour, and when melted together with gold at high temperatures, the surface becomes indistinguishable. He himself has been defrauded more than once.

The raw materials and recipes used for the fraud are no longer a secret.

CCTV reporters searched for rhenium powder on e-commerce and second-hand trading platforms, and the product pages were flagrant. The details directly stated "gold mixed with rhenium," "tested by fire and spectrometry," "gold weight increase," with sellers even writing ratios, "mixed with gold at 75 to 25." Reporters contacted one of the sellers, who guaranteed they could confuse the fake for the real, mixing 20% to 23%, which wouldn't be detected by market spectrometers.

One phrase on the product page caught the author's attention, called "gold amplification." Amplification sounds as if rhenium powder is some sort of lever tool.

What price do these rhenium powders have? Some sellers price high-purity rhenium powder at 29 yuan per gram, while those specifically labeled "gold mixing" sell for 150 yuan per gram. According to the testimonies of suspects in the Changxing case, their purchasing price is around 100 yuan per gram.

Is there a technical means to uncover this? Yes, but it's far from ordinary gold shops.

According to testing experiences from the Shaoxing Market Supervision Bureau in Zhejiang, high-precision imported spectrometers can separate the signals of rhenium and gold. Another method is more thorough: melting gold ornaments into gold water and sending them to authoritative institutions for testing. However, a professional in Shenzhen Shuibei told the Beijing News that most testing institutions in Shuibei use domestic devices worth tens of thousands, whose accuracy is limited, while authoritative institutions do not accept tests sent by individuals for destructive testing.

The equipment that can detect is unaffordable for ordinary gold shops. The affordable equipment cannot detect.

For thousands of years, the rule has been that gold is hard to counterfeit and easy to verify. One fire could provide the answer. Rhenium powder has reversed this relationship; it takes a few hours to manufacture a fake gold piece, while verifying a piece of real gold may require sending it to the laboratory and waiting several days.

Difficult to verify, easy to produce, it has a somewhat reverse Bitcoin feel.

High gold prices, busy fraud

Just doing the math reveals why so many people take risks.

The current gold recovery price is approximately 1040 yuan per gram. To make a 100-gram fake solid gold necklace with 20% rhenium, it requires 80 grams of genuine gold and 20 grams of rhenium powder. The cost of 80 grams of genuine gold is 83,200 yuan, and at the suspect's purchasing price of 100 yuan per gram for 20 grams of rhenium powder, that totals 2000 yuan. The total cost is 85,200 yuan, and if sold as solid gold, it will be 104,000 yuan.

A necklace nets nearly twenty thousand yuan.

This is still calculated at the recovery price. According to CCTV reports, some gangs specifically target small to medium-sized recycling shops, where the equipment is poor and the defense is weak, relying on fire and feel for the gold recovery process. Fraudsters also stage performances, crafting stories like "it was passed down from elders" or "I need money urgently due to losing a card game," creating a sense of urgency that relaxes the shop owner's vigilance.

The case in Hebi, Henan did exactly that. According to local police reports, two individuals, armed with rhenium-mixed necklaces, ran to three recycling shops in one day, making over 60,000 yuan. The second shop hadn't reacted yet, but the owner of the third shop detected irregularities and refused the transaction, causing the fraudsters to leave immediately. The entire process, from entering the shop to leaving, took no more than half an hour.

Not just the fraudsters are benefiting. The price of rhenium powder has also soared this year.

According to reports by The Paper, citing Wind data, the average daily price of rhenium powder was still 18,000 yuan per kilogram in June 2025, but it soared to 33,000 yuan by the end of July.

In one month, it increased by 83%.

Rhenium was originally a high-temperature alloy material in aircraft engines, legitimate industrial use. There are only about 2,400 tons of proven global reserves, mainly in Chile, the United States, and Russia, with 80% used in aerospace. However, analysts quoted by The Paper suggest that a portion of the current price increase is driven by speculators and fraudulent demands.

The higher the gold price, the stronger the "irregular demand" for rhenium, and rhenium prices rise accordingly.

A metal that should endure extreme high temperatures in engines is now being used most profitably to defraud the owners of recycling shops by mixing it into gold necklaces.

Counterfeits are everywhere

We are not unfamiliar with the term "knockoff."

The code for Bitcoin is open-source, and modifying a few parameters can create a new chain; Litecoin was created this way. The cost is almost zero, but at least it has its own name, its own price, and buyers know they are purchasing a knockoff currency.

Rhenium gold is also a knockoff, but it counterfeits the periodic table.

The atomic number of gold is 79, and that of rhenium is 75, a difference of 4 positions, with those 4 numbers conveniently falling within the blind spot of spectrometers. Mixing rhenium powder with gold in proportion, the resulting product claims to be solid gold in front of all conventional testing.

However, compared to knockoff coins, rhenium gold carries an additional layer of malice.

When you buy Litecoin, you know it’s not Bitcoin; when you have USDT, you know it’s not US dollars. Rhenium gold buyers do not have this opportunity; the instruments tell them it’s real, the invoices confirm it’s real, and even cutting open the necklace may not reveal the truth.

At least knockoff coins are openly branded as counterfeits. Rhenium gold not only duplicates but also swaps labels with genuine products.

According to an analysis of industry sources cited in an article on Zhihu, the current precious metal ornament testing standards do not even specify an upper limit for rhenium content, and law enforcement lacks basis. Rhenium is a legitimate industrial material, and its trade is legal; it’s impossible to prohibit a metal required in aviation engines from circulating in the market.

Gold prices are still rising, rhenium powder is still being sold, and spectrometer blind spots remain.

Many people buy gold for the assurance it provides. There’s no need for accounts, no need for online connectivity, and after decades of storing it at home, you can take it out and it’s still valuable. But this reassurance has a premise: you must ensure that what you have is genuine.

Previously, a single fire was enough; now you may have to melt the jewelry into gold water and send it to a laboratory.

If the cost of verifying a piece of gold is as troublesome as verifying a blockchain transaction, how much trust do the words "physical goods" still hold? Perhaps every individual accumulating gold should reevaluate.