Variscite is a relatively rare mineral, scientifically classified as a hydrated aluminum phosphate, cherished for its striking range of green colors. This ornamental stone, named after a historical region in Germany, typically presents as an opaque material with a waxy luster. The stone’s visual appeal is often enhanced by a distinctive matrix, which appears as webbing or splotches within the green mineral. Variscite has been utilized as a decorative material since ancient times.
Mineral Composition and Distinctive Physical Properties
Variscite is a hydrated aluminum phosphate with the chemical formula AlPO4 · 2H2O. The mineral typically forms in fine-grained masses, nodules, or crusts, though it belongs to the orthorhombic crystal system. Its attractive color spectrum ranges from pale lime green to deep emerald green, sometimes presenting with a bluish-green tint. This rich green coloration is primarily due to trace amounts of chromium present within the mineral structure.
Variscite ranks between 3.5 and 4.5 on the Mohs hardness scale, making it significantly softer than many common gemstones. Its specific gravity typically falls between 2.57 and 2.61. The stone usually exhibits opaque clarity, but some high-quality specimens may show slight translucency at the edges.
Geological Formation and Primary Sources
Variscite is a secondary mineral, meaning it forms through the alteration of pre-existing rocks rather than crystallizing directly from magma. Its formation requires phosphate-bearing water to react with rocks rich in aluminum, typically in a near-surface geological environment. This process usually results in the mineral forming in veins, cavity fillings, or rounded masses called nodules. The presence of other phosphate minerals, such as crandallite, often creates the white or yellowish veining.
Major sources for Variscite include the United States (Utah and Nevada), Australia, Germany, Brazil, and Spain. The Utah material is sometimes referred to by the trade name “Utahlite.” The black spider-web matrix found in some Nevada Variscite, and the intense emerald green of the Utah material, are particularly prized by collectors.
Variscite in Jewelry and Ornamental Uses
Variscite has historically been valued as a decorative material, with evidence of its use dating back to Neolithic times in Europe. Today, it is primarily cut into cabochons, which are polished, domed shapes, or used for small ornamental carvings. Its appealing color and relative ease of carving make it a favored material, particularly in Native American jewelry from the Southwestern United States.
The stone’s striking appearance often leads to confusion with green turquoise, but they are chemically different minerals. Turquoise is a copper aluminum phosphate, with copper providing its characteristic blue tones. Variscite is a pure aluminum phosphate, and its color palette leans exclusively toward the green end of the spectrum. This distinction is significant for identification, as Variscite’s green color is owed to chromium rather than copper.
Identifying Variscite
Identifying Variscite can be aided by observing its color, which is typically a purer green compared to the bluish-green of most turquoise. Its low rank on the Mohs scale is another indicator, as it is notably softer than turquoise, which rates higher. Due to the difficulty in distinguishing it from other minerals, professional gemological testing is often required for absolute certainty.
Caring for Variscite
Because of its relative softness and porous nature, Variscite requires specific care to maintain its appearance. It can be easily scratched, so jewelry pieces like rings or bracelets should be worn with caution and stored separately from harder materials. Cleaning should be done only with mild soap and lukewarm water, avoiding harsh chemicals, ultrasonic cleaners, and steam cleaners. Variscite is susceptible to discoloration from prolonged exposure to heat, sunlight, and even skin oils, making it better suited for pendants and earrings that have less direct contact with the skin.