1.62 ct BARRERITE – USA

Barrerite (Alaska)

Barrerite from the rugged, wave-battered coastlines of Alaska represents the “zeolitic-symmetry” peak of the silicate world. A rare sodium-rich member of the heulandite group, it is a species I have always respected for its “ice-white” to “glassy-clear” saturation and its status as a masterpiece of “orthorhombic” structural discipline. For the specialist, a top-tier Alaskan Barrerite is a prize of volcanic-marine focus; it offers a vitreous to pearly luster and a “luminous” presence that makes it a true “high-vibration” asset for the systematic vault. As an artist, I find the “aqueous” depth and the “razor-sharp” bladed architecture of these crystals to be one of nature’s most sophisticated and “ethereal” palettes.

The Heritage & Discovery

Historical Significance Barrerite is a vital species for understanding the subtle chemical shifts within the zeolite group, specifically the transition from monoclinic to orthorhombic symmetry due to high sodium content. Historically, it was named in 1974 after Richard M. Barrer, a New Zealand-born chemist and pioneer in zeolite research. In the world of fine minerals, it is celebrated for its natural, “arctic-neon” clarity, which stands as a symbol of mental focus and structural integrity. It serves as a reminder that the most “remote” geological environments can produce extraordinary crystalline results when sodium-rich hydrothermal fluids interact with volcanic host rocks.

Discovery While the species was first identified in Italy, the “gemmy” and “monumental” discoveries in Alaska redefined the mineralogical benchmark for the species’ size and quality. Scientifically, it is a hydrous sodium aluminum silicate. Its discovery on Kuiu Island provided mineralogists with the first clear look at the species’ potential for “water-clear,” well-terminated crystals that can reach several centimeters in length—a rarity for this species. My own respect for this material grew from observing its “optical” depth; specifically, the way the light catches the pearly cleavage faces—creating a “shimmer” that is unmistakable to the trained eye.

Important Mines The undisputed world capital for the finest, “museum-grade” Barrerite is the Rocky Pass area on Kuiu Island, within the Alexander Archipelago of Alaska. These Alaskan specimens set the global benchmark for color purity and “sharp” crystal architecture, often found in the cavities of basaltic and andesitic rocks. I also have a high regard for the rare finds from the Sardinia type-locality. For the vault, I prioritize the Alaskan material for its unmatched “crystalline-sharpness” and its status as a rare-location masterpiece of North American zeolite mineralogy.

Mineralogical Profile

Description Barrerite is a hydrous sodium aluminum silicate that crystallizes in the orthorhombic system. It sits at a 3 to 4 on the Mohs scale, making it a relatively soft mineral that must be handled with care to preserve its “razor-sharp” edges and pearly surfaces. It is characterized by its vitreous luster and its unmistakable, “colorless-to-snowy-white” color palette.

One of its most identifying traits is its tabular or bladed habit and its association with other zeolites in volcanic vesicles. It has a low refractive index and a specific gravity (SG approx 2.1 to 2.2) that reflects its light, hydrous structure. Because it forms in the cavities of volcanic rocks, it is often found in association with Stilbite, Heulandite, and Quartz. When I select a piece for the collection, I look for “pure” transparency and a lack of “internal veiling,” as these highlight the sophisticated, three-dimensional geometry of the mineral’s growth. It is a light, high-vibration mineral that offers a unique, “aqueous-neon” beauty unlike any other silicate variety.

Chemical Formula Na2(Al2Si7O18) · 6H2O