Diamonds, a crystalline form of pure carbon, hold a unique place in human culture as symbols of permanence and luxury. The question of whether these stones are truly rare is complex, depending on geology, the volume of material mined, and the economic forces that shape the consumer market. Understanding diamond scarcity requires looking beyond the mystique to examine the intense natural processes of formation, the distinction between different grades of stone, and the powerful role of market control.
Geological Conditions and Natural Distribution
The formation of natural diamonds requires a very specific and extreme set of conditions found deep within the Earth’s mantle. Carbon atoms must be subjected to temperatures around 1,000 to 1,300 degrees Celsius and pressures exceeding 50 kilobars. This environment exists only at depths greater than 150 kilometers, primarily beneath the oldest, most stable sections of the continental crust known as cratons. These conditions mean that diamond deposits are not widespread, contributing to their natural scarcity. Diamonds remain deep until they are rapidly brought to the surface through rare, violent volcanic eruptions.
These eruptions create structures called kimberlite pipes, which act as the geological elevator. The speed of the eruption is paramount; if the ascent were slow, the diamonds would revert to graphite. Kimberlite pipes are the primary source rock for most mined diamonds, but only a small fraction contain enough gem-quality material to be economically viable.
The Distinction Between Gem and Industrial Volumes
The vast majority of material extracted from diamond mines is not the brilliant gemstone seen in jewelry, but rather a lower-grade material used in industry. Typically, less than 20% of all diamonds mined globally are classified as gem-quality stones. The remaining 80% or more are designated as industrial-grade diamonds, sometimes called “bort.” These industrial diamonds are valuable due to their inherent hardness, making them suitable for specialized applications like drill bits, cutting tools, and abrasive powders.
The difference between the two categories is determined by physical characteristics, often summarized by the “Four Cs”: color, clarity, cut, and carat weight. Stones with significant internal flaws, poor color saturation, or irregular shapes are diverted away from the jewelry market. For a diamond to be considered gem-quality, it must possess the transparency and structural integrity necessary for cutting and polishing. The percentage of diamonds that are colorless and flawless enough to command the highest prices is minuscule. This distinction is fundamental to diamond rarity, as the perceived scarcity applies only to this small, high-quality subset.
Market Control and Artificial Scarcity
The high price and perceived rarity of gem diamonds have historically been maintained by strategic economic control over the supply chain. Following the discovery of massive deposits in South Africa, which threatened to flood the market, a dominant entity established a near-monopoly. This control was designed to prevent the natural decline in prices that would follow such a large influx of supply.
This entity, which controlled approximately 80-90% of the world’s rough diamond supply, accomplished this through managed distribution. The strategy involved stockpiling large quantities of diamonds and releasing only a controlled amount to the market. This deliberate restraint created an artificial scarcity, ensuring that demand consistently outpaced the available supply and kept prices elevated.
In parallel, the industry launched successful marketing campaigns, notably coining the slogan “A Diamond Is Forever” in 1947. This campaign linked the diamond to eternal love and status, transforming the stone into a cultural requirement for engagement. By discouraging the resale of diamonds, the industry also removed a potential secondary market that could have challenged the illusion of scarcity.
The Influence of Laboratory-Created Diamonds
The emergence of laboratory-created diamonds presents the most significant modern challenge to the long-standing narrative of diamond rarity. These stones are not simulants; they are chemically, physically, and optically identical to their mined counterparts, sharing the same pure carbon crystalline structure. They are grown in controlled environments using two primary methods: High Pressure High Temperature (HPHT) and Chemical Vapor Deposition (CVD).
The HPHT method mimics the Earth’s natural formation process using extreme pressure and heat. The CVD method grows the diamond layer by layer from a carbon-rich gas plasma. Both processes can produce gem-quality stones in weeks or months, bypassing the geological timescale of millions of years. This technological capability introduces a theoretically unlimited supply source, fundamentally altering the scarcity equation.
Because lab-grown diamonds are produced with greater efficiency and no mining costs, they are offered at significantly lower prices than equivalent natural stones. This has forced the traditional diamond industry to emphasize the “origin” of a stone as the new definition of rarity. Consequently, the value proposition for natural diamonds is now tied to their geological provenance and the concept of a finite, Earth-mined resource.