Rowleyite

rowleyite

antipinite

struvite

vanadinite

Images

Formula: [Na(NH4,K)9Cl4][V5+,4+2(P,As)O8]6.n[H2O,Na,NH4,K,Cl]
Vanadate, arsenic-bearing mineral
Crystal system: Isometric
Specific gravity: 2.23 measured
Hardness: 2
Streak: Brownish green
Colour: Very dark brownish green
Environments

Hydrothermal environments

Rowleyite is a relatively new mineral, approved in 2016 and to date (September 2025) reported only from the type locality.

Localities

At the type locality, the Rowley Mine, Theba, Painted Rock Mining District, Painted Rock Mountains, Maricopa County, Arizona, USA, rowleyite was found in an unusual low-temperature, apparently post-mining suite of phases that include various vanadates, phosphates, oxalates and chlorides, some containing (NH4)+. Other secondary minerals found in association with rowleyite include antipinite, fluorite, mimetite, mottramite, quartz, salammoniac, struvite, vanadinite, willemite and wulfenite. Antipinite in association with rowleyite is consistent with a bat guano source.
Crystals of rowleyite are very dark brownish green (appearing black) truncated octahedra up to about 50 μm across. The streak is brownish green, the lustre is vitreous, and very thin fragments are transparent; there is no cleavage.
The crystal structure of rowleyite contains [V4O16]12+ polyoxovanadate units. The rowleyite framework is among the most porous known. (AM 102.1037-1044).
Rowleyite from the Rowley Mine - Image

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