Rhodium is found in America primarily as a byproduct of platinum group element (PGE) mining, with significant deposits and mining activity in the Stillwater Complex in Montana (USA) and the Sudbury Basin in Ontario (Canada), also in natural river sands, though South Africa remains the dominant global source, with US/Canadian output being much smaller.
The largest rhodium deposits are scattered across the globe, most commonly found in South Africa, Russia, and North America. South Africa is the dominant producer, accounting for nearly 80% of global rhodium output.
The “common knowledge” about rhodium is that it is most commonly found in automobile catalytic converters.
Rhodium is found in platinum or nickel ores with the other members of the platinum group metals. It was discovered in 1803 by William Hyde Wollaston in one such ore, and named for the rose color of one of its chlorine compounds.
Although the underlying metal may be magnetic, the rhodium plating itself is not magnetic. Thus, if you have a piece of jewelry that has been rhodium plated, it will not be magnetic.
Rhodium is used for several different things, such as automobiles, jewelry, searchlights, electronics and mirrors. By far the most common use is in catalytic converters, which are exhaust emission control devices that look like a small muffler on the outside of a vehicle.
RHODIUM (METAL FUME) is flammable. Acts as a reducing agent. Reacts violently with BrF5, ClF3 and OF2. Reacts with fluorine, with chlorine (when heated), hydrogen peroxide, sulfur dioxide (when heated), and nitrogen dioxide.
In particular, there is a high demand around the world for platinum, palladium, and rhodium—rare precious metals found inside the catalytic converters. Their job is to help ensure that the unburned residues of carbon monoxide, hydrocarbons, or nitrogen oxides are oxidized and neutralized.
A typical catalytic converter contains approximately 1–2 grams of rhodium, but this number fluctuates based on vehicle class, design, and age.
The rarest metal on Earth is often considered rhodium, though iridium and osmium are also contenders, all part of the Platinum Group Metals (PGMs); rhodium is incredibly scarce (around 0.000037 ppm in the crust) and valuable, primarily used in catalytic converters, while iridium is valued for extreme hardness and corrosion resistance, and osmium is the densest, making them all extremely rare and expensive.
Rhodium compounds may produce kidney damage and toxic symptoms of the central nervous system. Rhodium compounds are encountered relatively rarely by most people. There are almost no reported cases of human being affected by this element in any way. However all rhodium compounds should be regarded as potentially toxic.
Rhodium prices are dropping due to a combination of increased supply (from better mining recovery and recycling) and weakening demand, primarily driven by the shift towards electric vehicles (EVs) which use fewer internal combustion engine (ICE) catalytic converters, plus technological advancements reducing its use in other areas like fiberglass, and significant inventory destocking from major players like Chinese manufacturers. High prices previously incentivized efforts to use less rhodium, leading to a significant price collapse from its peak.
Raw rhodium is a sight to behold, characterized by its silvery-white sheen that exudes an almost mirror-like quality. This rare metal, part of the platinum group, stands out not just for its scarcity but also for its striking visual appeal.
While rhodium is extremely valuable (often the most expensive precious metal), Californium is significantly more expensive, costing hundreds of millions per ounce due to its rarity and use in nuclear technology, with Iridium and sometimes other rare elements like Osmium also topping its price, though prices fluctuate.
Found generally in two different places, catalytic converters, and jewelry. Rhodium is used to be coated onto gold jewelry to be able to create “white gold.” The primary use for Rhodium is in the catalytic converter market and is helped to negate the fumes and emissions from car engines.
Rhodium belongs to the platinum metal family and is known for being very scarce, having a high price in the market, and being used in many industries.
Rhodium's all-time high occurred in March 2021, reaching nearly $30,000 per ounce, driven by extreme demand for automotive catalytic converters due to stricter emissions regulations, combined with limited supply from major producing regions like South Africa. This price surge made it significantly more expensive than gold, though it has since fallen, with prices fluctuating in the thousands of dollars, but remaining highly volatile.
Never mix hydrogen peroxide with bleach, ammonia, vinegar, or rubbing alcohol, as this creates toxic fumes (like chloramine or chloroform) or highly corrosive peracetic acid, causing severe irritation or worse. Also avoid mixing it with certain metals (iron, copper, brass) or organic materials due to fire/explosion risks, and always use it in well-ventilated areas with gloves.
Aqua regia has been used for the dissolution of rhodium alloy samples.
Some of the most common sources of scrap gold and silver include jewelry and watches, but many people fail to see what they are worth. Broken chain, mismatched earrings, and old watch stuck in a drawer — these things may hold precious metals worth recycling.
The most common uses for rhodium include automotive catalytic converters, chemical catalysts, electrical contacts, reflective coatings, and for plating white gold, silver, and other jewelry.