Platinum is a rare and precious metal, valued for its unique properties. This dense, malleable, and corrosion-resistant element is a PGM. Its properties make it indispensable in applications like catalytic converters, fine jewelry, and advanced electronics. Platinum’s natural scarcity, found at about 0.005 parts per million in Earth’s crust, contributes to its high demand and economic importance. Understanding the geological processes that concentrate this dispersed element into viable deposits is important.
Global Platinum Distribution
In 2022, global platinum mine production reached approximately 188.5 metric tons, with a concentrated distribution among a few nations. South Africa was the world’s foremost producer, contributing 74.3% (140 metric tons) of the global supply. This dominance is due to its extensive geological formations rich in platinum group elements, particularly the Bushveld Complex. Russia was the second-largest producer, accounting for about 10.6% (20 metric tons), primarily from the Norilsk-Talnakh region.
Zimbabwe held the third position in global platinum production, yielding 15 metric tons (8% of the total), largely from its Great Dyke geological feature. Canada ranked as the fourth-largest producer, with its mines yielding six metric tons (3.2% of global output). Canadian production often comes as a co-product of nickel mining in regions like the Sudbury Basin. The United States also contributed to the global supply, producing 3.3 metric tons (1.8% of the world’s platinum). These five nations collectively are responsible for nearly 97.8% of the world’s platinum mine production, underscoring the geographically constrained nature of this valuable resource.
Geological Environments of Platinum
Platinum Group Elements (PGEs), including platinum, predominantly form in specific geological settings that facilitate their concentration from dispersed states. The most significant type of platinum deposit is associated with mafic and ultramafic igneous rocks. These rock types, characterized by high magnesium and iron content and low silica, originate deep within the Earth’s mantle and are subsequently brought closer to the surface through tectonic processes.
Within these igneous environments, platinum ore occurs within large, layered intrusions. These layered igneous bodies develop as magma cools and crystallizes within the Earth’s crust, leading to the gravitational settling and accumulation of dense, metal-rich minerals into distinct stratigraphic layers. Platinum is found in close association with sulfide minerals such as pyrrhotite, pentlandite, and chalcopyrite. These immiscible sulfide droplets scavenge and concentrate PGEs like platinum during the cooling and differentiation of the magma, forming economically viable ore bodies.
Another notable geological environment for platinum is secondary placer deposits. These deposits originate from weathering and erosion of primary platinum-bearing rocks. Dense platinum particles are then transported by water, often over long distances, and concentrated in riverbeds, alluvial plains, or ancient stream channels due to their high specific gravity. Historically, these alluvial concentrations were important for early platinum discoveries. While magmatic processes are the primary mechanism for significant platinum ore formation, hydrothermal fluids can also circulate through fractures in the Earth’s crust and precipitate PGEs as they cool and react with surrounding rocks.
Major Platinum Mining Regions
The Bushveld Igneous Complex in South Africa is the world’s most significant platinum mining region, hosting over 70% of known platinum resources. This vast, two billion years old, layered igneous intrusion is known for its geological structure that facilitates the concentration of platinum group elements. Within the Bushveld Complex, the primary ore bodies are the Merensky Reef, the Upper Group 2 (UG2) Reef, and the Platreef, each representing distinct mineralized layers. The Merensky Reef has been a substantial source since 1925, while the UG2 Reef, commencing production in the 1970s, has become the largest platinum mine globally.
Norilsk-Talnakh in Russia is another major platinum mining region, known for its nickel-copper sulfide ores that contain significant amounts of platinum and palladium. The mines in the Taimyr Peninsula of Siberia are responsible for the majority of Russia’s current platinum production. These deposits feature magmatic sulfide mineralization where platinum group elements are concentrated within the sulfide melt.
Zimbabwe’s Great Dyke is a prominent linear geological feature extending over 550 kilometers, a rich source of platinum group metals, including platinum. Major mining operations along the Great Dyke include Zimplats, Mimosa Mining Company, and Unki Mine, contributing to the country’s economy. The Darwendale platinum project, also within the Great Dyke, is one of the largest undeveloped PGM deposits globally.
In Canada, the Sudbury Basin in Central Ontario is a notable source of platinum. While platinum is often recovered as a co-product during nickel mining in Canada, the Sudbury Basin is known for its platinum-bearing deposits, which are believed to have formed from ancient meteorite impacts and associated volcanic activity. Other Canadian platinum sources include the Raglan nickel mine in Quebec and the Lac des Iles mine in Western Ontario, diversifying the global supply.