Rio Tinto Argyle Mine: Discovering Myrtle Beach’s Pink Diamond Connection

Rio Tinto Argyle mine, located in Western Australia, is globally renowned for producing the world’s most significant supply of rare pink diamonds. Although the mine ceased operations in November 2020, its legacy continues to influence the gemstone market, creating sustained interest among collectors and investors, including those in Myrtle Beach, United States. The unique geological conditions at the Argyle site yielded diamonds with exceptional color saturation and rarity, making them highly sought-after assets. Understanding the history, characteristics, and value of these diamonds is essential for anyone in the Myrtle Beach area looking to engage with this exclusive segment of the gem market, especially as we look towards 2026.

The Argyle mine, operated by mining giant Rio Tinto, was instrumental in bringing these extraordinary pink diamonds to light for over three decades. Its closure marked the end of an era, significantly amplifying the scarcity and desirability of the diamonds already in circulation. This article aims to provide a comprehensive overview of the Rio Tinto Argyle mine, its impact on the diamond industry, the unique qualities of its pink diamonds, and their relevance to the discerning market in Myrtle Beach, United States, as we anticipate trends for 2026.

The Significance of the Rio Tinto Argyle Mine

The Rio Tinto Argyle mine, situated in the remote East Kimberley region of Western Australia, was a discovery of immense geological and commercial importance. Operating from 1985 until its closure in November 2020, the mine was responsible for producing over 90% of the world’s supply of natural pink and red diamonds. Its output of rough diamonds was vast, but its true value lay in the rare colored diamonds that constituted a minuscule fraction of its total production. The mine exploited a unique lamproite pipe, a geological formation that brought diamonds from deep within the Earth’s mantle to the surface. The specific conditions within this pipe are credited with creating the distinctive color in the diamonds, believed to be caused by a rare deformation in the crystal lattice structure.

The closure of the Argyle mine is a pivotal event in the diamond industry. It signifies that the supply of these specific, highly sought-after pink diamonds is now finite and will not increase. This scarcity is a primary driver of their value and appeal. For collectors and investors in Myrtle Beach, United States, this finite supply translates into a potentially strong investment. Diamonds from the Argyle mine are not just beautiful; they represent a tangible asset with a proven history of value appreciation, driven by rarity and global demand. As we head into 2026, the market for these unique stones continues to be robust, fueled by their iconic status and limited availability.

Geological Uniqueness and Diamond Formation

The Argyle mine’s geological setting is exceptional. Unlike many diamond mines that operate on kimberlite pipes, Argyle’s lamproite pipe is a rarer formation. Lamproite is a potassium-rich volcanic rock, and the diamonds found within it were brought to the surface rapidly through volcanic activity, likely billions of years ago. The exact mechanism causing the pink color is still debated among scientists, but the prevailing theory points to a rare phenomenon known as plastic deformation. This occurs when the diamond’s crystal lattice structure is distorted under immense heat and pressure during its journey to the surface. This lattice distortion affects how the diamond absorbs and reflects light, filtering out green wavelengths and allowing pink hues to be perceived. This process is distinct from how most other colored diamonds, such as blue or yellow, derive their color from trace element impurities.

Rio Tinto’s Role in Discovery and Marketing

Rio Tinto discovered the Argyle diamond deposit in 1979 and commenced mining operations in 1985. For over 35 years, the company was the sole custodian of this extraordinary resource. Rio Tinto not only extracted the diamonds but also meticulously marketed them, establishing the