Platinum is a rare and valuable precious metal, a lustrous, silver-white transition metal. It is remarkably dense, malleable, and ductile, and exhibits exceptional resistance to corrosion and tarnish, even at high temperatures. These characteristics contribute to its broad utility and high demand, making it highly sought after for various applications, including jewelry, automotive components, and industrial catalysts.
The First Encounters with Platinum
Human interaction with platinum dates back centuries, predating its formal recognition in Europe. Pre-Columbian civilizations in South America, particularly in modern-day Ecuador and Colombia, used naturally occurring platinum for decorative items. These early artisans demonstrated sophisticated metallurgical skills, incorporating the metal into their crafts. The first European accounts appeared in the 16th century from Spanish explorers mining gold in Colombia’s Chocó region. They initially regarded this whitish metal as an unwanted impurity, calling it “platina,” meaning “little silver.”
Platinum gradually gained scientific attention in Europe during the 18th century, as researchers began to investigate its unusual resistance to melting and corrosion. Spanish scientist Antonio de Ulloa published a report on the metal in 1748, marking a significant step in its scientific investigation. Swedish assayer Henrik Scheffer provided a detailed scientific description in 1752, recognizing platinum as a distinct element. Further discoveries in the early 19th century, notably in Russia’s Ural Mountains, made platinum more accessible for industrial and scientific uses.
How Platinum Forms in the Earth
Platinum’s formation is intricately linked to specific geological processes occurring deep within the Earth’s crust. Most primary platinum deposits are associated with mafic and ultramafic igneous rock intrusions. These rocks originate from molten magma that cools and solidifies, often within large, layered formations. During this cooling, magmatic differentiation occurs, where dense platinum group elements (PGEs) like platinum, palladium, and rhodium concentrate and crystallize from the magma.
This process often involves sulfide liquid separating from silicate magma, concentrating PGEs into rich ore bodies within these layered intrusions. Beyond these primary magmatic deposits, platinum is also found in secondary placer deposits. These form when primary platinum-bearing rocks weather and erode, releasing the metal. Dense platinum particles are then transported by rivers and streams, accumulating in riverbeds and alluvial plains.
Where Platinum is Found Today
While historical discoveries were important, the majority of the world’s platinum production today originates from a few key geological regions. South Africa’s Bushveld Igneous Complex holds the largest known platinum reserves globally, accounting for approximately 70% to 75% of the world’s platinum resources. This massive, two-billion-year-old layered intrusion contains significant concentrations of platinum group metals within specific layers, such as the Merensky Reef and the UG2 Reef.
Another significant source is Russia’s Norilsk-Talnakh deposits, where platinum is found in association with nickel-copper sulfide ores. These deposits represent a major contributor to the global platinum supply. Zimbabwe’s Great Dyke is also a notable layered mafic intrusion, stretching over 550 kilometers and containing substantial platinum group metal deposits, making Zimbabwe the third-largest global producer. In North America, Montana’s Stillwater Complex is a large layered intrusion that contains significant platinum and palladium resources, primarily in its J-M Reef.