Pink diamonds are among the most captivating and highly sought-after gemstones in the world. Their distinctive hue has led many to question their origin and whether these colored diamonds occur naturally. The answer is yes, natural pink diamonds do exist, and they are a product of unique geological processes deep within the Earth.
The Science Behind Pink Color
The color of pink diamonds arises from a unique phenomenon known as plastic deformation in their crystal structure. Unlike most other colored diamonds, which get their color from chemical impurities, pink diamonds do not. Instead, intense pressure and heat during their formation and ascent to the Earth’s surface alter the diamond’s atomic structure.
This stress permanently changes the crystal lattice without breaking it, creating “graining” or “slip planes” within the diamond. These irregularities affect how the diamond absorbs and reflects light, allowing the pink hue to become visible. The geometry of these deformations influences the intensity and shade of pink, from faint blush to deep magenta. This phenomenon occurs at depths of 150–200 kilometers, where pressure twists the diamond’s lattice.
Rarity and Market Value
Natural pink diamonds are exceptionally rare, constituting less than 0.01% of all diamonds mined globally. This scarcity contributes to their high market value, making them among the most valuable gemstones.
The closure of the Argyle Mine in Australia, the source of most pink diamonds, further amplified their rarity and driven prices upward. High-quality pink diamonds, especially intense and vivid ones, command much higher prices per carat.
Identifying Natural vs. Treated Pink Diamonds
Distinguishing between natural pink diamonds and treated or laboratory-grown alternatives requires specialized gemological expertise. Lab-grown pink diamonds share the same chemical composition and crystal structure as natural ones but are created in controlled environments and are generally more affordable. Treated natural diamonds, often initially off-color stones, can undergo processes like high-pressure, high-temperature (HPHT) treatment or irradiation to induce a pink hue.
Gemologists use various methods to identify these differences. Examination under a microscope can reveal inclusions, growth patterns, or “graining” typical of natural formation. Spectroscopic analysis analyzes light absorption patterns, indicating if the color is natural or a result of laboratory treatment. Certification from a reputable gemological laboratory, such as the Gemological Institute of America (GIA), is important for verifying a pink diamond’s authenticity, origin, and color grade.
Primary Global Sources
Historically, natural pink diamonds have been discovered in various locations, though often in sporadic and limited quantities. Early discoveries were made in India, particularly from the Kollur Mine in the 17th century, and later in Brazil during the 17th and 18th centuries. Other countries where pink diamonds have been found include South Africa, Russia, Canada, and Tanzania.
The Argyle Mine in Western Australia was the most significant source, producing over 90% of the world’s supply while operational. The Argyle Mine, which ceased operations in November 2020, yielded a spectrum of pinks from delicate pastels to deep purplish-pinks.