Platinum is significantly rarer than gem-quality diamond when measured by its concentration in the Earth’s crust and the geological difficulty of its formation. While both materials command high values and are challenging to mine, platinum’s scarcity is an inherent property of the element itself. Diamond supply, conversely, is more influenced by the distinction between common industrial-grade stones and the select few that qualify as gem-quality. This comparison must be viewed through a geological lens, looking beyond market price or annual production figures.
Defining Geological Rarity
True geological rarity is measured by an element’s or mineral’s concentration within the Earth’s crust. Scientists express this concentration in parts per million (ppm) or parts per billion (ppb), representing the material’s presence per million or billion units of surrounding rock. An element is considered geologically rare if its crustal abundance is extremely low, making it difficult to find concentrated deposits. This intrinsic scarcity must be distinguished from ‘availability,’ which refers to how easily a material can be located and processed into an economically viable product.
The Scarcity of Platinum
Platinum is one of the rarest elements in the Earth’s crust, with an average concentration of only about 0.005 parts per million. This extreme scarcity results from the element’s siderophile, or “iron-loving,” nature. During Earth’s formation, the vast majority of platinum sank with iron to form the planet’s core, leaving the crust highly depleted.
The small quantities that remain are typically found in extremely localized, massive igneous intrusions, such as the Bushveld Igneous Complex in South Africa. South Africa’s reserves account for the majority of the world’s known platinum, though Russia and the United States hold other significant deposits. Extraction requires processing vast quantities of ore to yield a single ounce of the metal, often taking several months of complex refining. This combination of low crustal abundance and geographically limited deposits establishes platinum as a metal of profound geological scarcity.
The Availability of Diamonds
Diamonds are crystals of carbon that form deep in the Earth’s mantle, requiring immense pressure and temperatures over 1,000 degrees Celsius. They are transported rapidly to the surface through rare, violent volcanic eruptions, solidifying into cone-shaped formations known as kimberlite and lamproite pipes. These pipes are the only primary source of diamonds and are found primarily in ancient, stable continental shields, or cratons.
While the mechanisms that bring diamonds to the surface are geographically restricted, the sheer volume of material that is technically a “diamond” is substantial. Rough diamond production totals tens of millions of carats annually. The crucial factor influencing the market is the distinction between industrial-grade and gem-quality stones, as only 20 to 30 percent of all mined diamonds meet the standards for jewelry. Industrial diamonds, which are often flawed or too small, are common and used extensively in tools for their hardness.
The limited availability of flawless, colorless material used in jewelry creates the perception of extreme rarity. However, the raw mineral itself is not as inherently scarce as the platinum element within the Earth’s crust.
Synthesis of Rarity
The geological data confirms that platinum is the rarer material when comparing fundamental crustal concentration. Platinum’s natural abundance is measured in parts per billion, reflecting a true, planet-scale depletion of the element. Its scarcity is universal, defined by the physics of planetary formation.
In contrast, the rarity of a diamond is largely a function of its quality grading, as the raw mineral is produced in much higher volumes than the metal. A flawless, large diamond is exceptionally rare, but the element carbon is ubiquitous. The economic viability of platinum mining depends on finding localized deposits of a globally scarce element, while diamond mining relies on finding deposits that contain a sufficient fraction of a high-value mineral.