0.72 ct AUGELITE – PERU

Augelite

Augelite is a gemstone that represents the pinnacle of “ethereal” clarity within the phosphate group. An aluminum phosphate hydroxide, it is a mineral I have always held in high regard for its “ghostly” transparency and its remarkably sharp, monoclinic crystals. While most phosphates are opaque and earthy, gem-quality Augelite possesses a vitreous to pearly luster and a “liquid-light” appearance that can rival fine Topaz or Goshenite. It typically presents as colorless, pale yellow, or a delicate “sea-foam” green. For the specialist, Augelite is a prize of chemical purity and structural rarity—it is the “diamond” of the phosphate world, offering a sophisticated, geometric brilliance that is exceptionally elusive in large, clean crystals.

The Heritage & Discovery

Historical Significance: Augelite is a vital species for understanding the behavior of aluminum in hydrothermal and metamorphic phosphate systems. Historically, it was a rare curiosity until the discovery of spectacular, large-scale crystals in the mid-20th century. In the world of fine minerals, it is celebrated for its incredible lustrous cleavage, standing as a favorite for those who value the “architectural” side of mineralogy. It stands as a symbol of clarity and high-frequency vibration, bridging the gap between common phosphate ores and the elite world of rare, faceted collector gems. It serves as a reminder that the most humble chemical groups can produce masterpieces of crystalline perfection when conditions are perfectly balanced.

Discovery: The mineral was first described in 1868 and was named from the Greek auge, meaning “luster” or “brilliance,” in direct reference to the high-gloss sheen of its cleavage surfaces. The type-locality is Västanå, Skåne, Sweden. Scientifically, it is a basic aluminum phosphate. Its discovery provided mineralogists with the first clear look at a “high-luster” aluminum phosphate, helping to map the diversity of species found in complex metamorphic suites and peraluminous hydrothermal veins.

Important Mines: The legendary source for world-class, “gem-clear” Augelite is the Champion Mine in the White Mountains of California, USA. I also have a high regard for the spectacular, large crystals found in the Rapid Creek region of the Yukon, Canada, and the pristine specimens from the Mundo Nuevo Mine in Peru. For the vault, I prioritize the Peruvian material for its exceptional crystal size and transparency, and the Yukon specimens for their unique association with other rare phosphates like Lazulite.

Mineralogical Profile

Description: Augelite is an aluminum phosphate hydroxide that crystallizes in the monoclinic system. It sits at a 4.5 to 5 on the Mohs scale, making it a relatively soft mineral that should be protected from physical shock and acids. It is characterized by its vitreous luster on crystal faces and a magnificent pearly luster on its cleavage planes.

One of its most identifying traits is its perfect cleavage and its “water-clear” transparency. It has a moderate refractive index (approx 1.57 to 1.59), which contributes to its soft, “inner” glow when light passes through the crystal. Because it is an aluminum-rich phosphate, it is often found in association with Pyrophyllite, Lazulite, and Rutile. When I select a piece for the collection, I look for “sharp” tabular terminations and an absolute lack of internal veining, as these highlight the sophisticated, three-dimensional geometry that makes Augelite a standout for the systematic specialist. It is a light, high-vibration mineral that offers a unique, “icy” beauty unlike any other phosphate species.

Chemical Formula: Al₂(PO₄)(OH)₃