Wilcoxite is a rare and complex phosphate mineral that belongs to the apatite group. It is named after Professor Roy A. Wilcox, an American mineralogist who extensively studied phosphate minerals. Wilcoxite typically forms as small, tabular to equant crystals or as compact masses in geological formations.
Physically, wilcoxite is opaque with a vitreous to greasy luster. Its color ranges from creamy white to pale brown, although it may appear colorless in thin fragments. The mineral exhibits a brittle tenacity and has a Mohs hardness of 5.5-6, making it relatively hard but not exceptionally resilient. It typically has a white streak.
Wilcoxite is commonly found in phosphate-rich environments, often occurring as an accessory mineral within phosphatic pegmatites or in association with other phosphate minerals like xenotime and lazulite. It typically forms through the alteration of primary phosphate minerals during metamorphic or hydrothermal processes.
Chemically, wilcoxite comprises calcium, manganese, iron, and aluminum, combined with phosphate and hydroxide ions. Its chemical formula is typically written as Ca(Na,REE)(Fe3+,Mn,Al2+)(PO4)2(OH)1-x, where Na represents sodium, REE denotes rare earth elements, Fe3+ refers to trivalent iron, Mn represents manganese, Al2+ denotes divalent aluminum, PO4 represents phosphate, OH denotes hydroxide, and x ranges from 0 to 1.
While wilcoxite may not have extensive industrial or commercial applications due to its scarcity, it remains an important mineral for scientific research and mineralogical studies, contributing to our understanding of geological processes and the formation of phosphate deposits.
