Beraunite
Beraunite is a phosphate mineral in which iron sits in the Fe3+ state, often forming hydrated, phosphate-rich assemblages. It typically appears as yellow to orange-brown, brownish-orange, or reddish-brown crystals, commonly with a vitreous to silky lustre and a relatively complex, often elongated habit. The mineral crystallizes in environments where phosphate-rich fluids interact with iron-bearing rocks, and its structure includes hexagonal sheets linked by hydroxyl and oxide groups, with water molecules occupying interlayer sites. Well-formed crystals can display distinct color zoning and variable transparency, making specimens attractive to mineral collectors.
- Formula
- Fe3+6(PO4)4O(OH)4 · 6H2O
About Beraunite
Notable specimens come from the United States and Sweden, where localities have yielded well-crystallized barged, prismatic, and tabular forms. The Swedish occurrences, in particular, have contributed to the species’ popularity among collectors who value rare hydration states and nuanced color due to varying iron oxidation. In the United States, classic mine exposures offer sizeable, lustrous crystals that showcase the mineral’s minerals and phosphatic character. Collectors seek beraunite for its combination of metallic luster, earthy color tones, and the insight it provides into oxidation and phosphate-rich mineral systems, along with the anticipation of finding well-formed crystals from distinctive localities.