Metaheinrichite Dimensions: 8.8 cm × 4.8 cm × 4.6 cm Locality: White King Mine, Lakeview, Lake County, Oregon, USA Description: Metaheinrichite is a very rare hydrated barium uranium arsenate that is found in less than two dozen world localities, most of which are in Germany. The co-type locality for the species is the White King Mine in Lake County, Oregon (the other is Wittichen, Baden-Württemberg, Germany). The piece hosts many tiny, bladed, beautiful yellow colored crystals of translucent metaheinrichite sitting on host rock matrix. While the crystals are small, you can see them with the naked eye, and the piece shows beautiful fluorescence under UV light. A cool, colorful rarity. From the worldwide collection of David Burgess (1951-2016). David was a prolific species collector from Newington, Connecticut, and the namesake for the extremely rare cobalt arsenate species burgessite, which he discovered. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Metaheinrichite
Metaheinrichite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Ba(UO₂)₂(AsO₄)₂·8H₂O.
It crystallizes in the tetragonal crystal system (space group P2_1).
Key properties: Mohs hardness 2.5; specific gravity 4.04; Pale yellow to white streak; Vitreous to pearly luster; optically uniaxial.
IMA symbol Mhrc, grandfathered status — known before the IMA’s founding, named in 1958.
A rare secondary mineral derived by the weathering of primary uranium minerals.
It is found associated with Heinrichite, zeunerite, nováčekite, erythrite, arseniosiderite, pitticite.
The prefix meta- denotes the dehydration product of heinrichite.