Rhodium is a silver-white metallic element with chemical symbol Rh and atomic number 45. It belongs to the group of precious metals and is one of the rarest metals found on earth. Rhodium occurs naturally mainly in platinum and chrome ores, and is most often found in Russia, South Africa and Canada.

Rhodium is an extremely hard and durable metal, with a high melting point of 1964 degrees Celsius. It also has a high reflectivity and is sometimes used as a coating material on other metals to give them a high gloss finish.

Rhodium is mainly used in the automotive industry, especially in catalytic converters. Rhodium has a very high catalytic activity and is therefore very effective in reducing harmful emissions from vehicles.

Due to its rare and limited abundance on Earth, rhodium is one of the most expensive precious metals in the world. The price of rhodium can vary greatly depending on demand and availability on the market.

A catalyst containing higher levels of rhodium is more expensive due to its high cost. However, due to its high efficiency in reducing vehicle emissions, the use of rhodium in catalytic converters has become increasingly common.

In summary, rhodium is an unusual and sought-after metal used primarily in the automotive industry to reduce harmful emissions. Its high cost is due to its rarity and limited occurrence on Earth