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Formula: [Pb4(OH)4](NO3)4
Nitrate
Specific gravity: 5.297 calculated for the empirical formula and 5.133 for the ideal formula
Hardness: 2½
Streak: White
Colour: Colourless, brown
Solubility: At room temperature, nitroplumbite appears to decompose in water, but does not dissolve; it dissolves slowly
in dilute hydrochloric acid
Environments
Sedimentary environments
Hydrothermal environments
Nitroplumbite is a new mineral, approved in 2021 and to date (October 2022) reported only from the type locality.
Localities
The type locality, the Burro mine, Slick Rock Mining District, San Miguel County, Colorado, USA, is in an area where
uranium and vanadium minerals occur together in
sandstone. The uranium and
vanadium minerals, along with a variety of sulphides, were deposited where
solutions rich in uranium and vanadium encountered pockets of strongly
reducing solutions that had developed around accumulations of carbonaceous plant material.
Nitroplumbite is rare. It occurs on asphaltite and
montroseite- and
corvusite- bearing
sandstone in association with
baryte, chalcomenite,
volborthite, and an unidentified lead-nitrate phase. In the Burro mine
diverse secondary assemblages form on tunnel walls from aqueous
solutions of relatively low pH (acid) under ambient temperatures and generally oxidising, near-surface conditions.
Nitroplumbite occurs in such a secondary assemblage, but
one that exhibits local enrichment in lead and nitrogen (as well as
selenium). Galena and
clausthalite have been reported to occur at the Burro mine and either or
both of these may have contributed the original lead, although it may have also
been, in part, sourced as product of radiogenic decay. The nitrogen was likely sourced from the carbonaceous plant
material.
The nitroplumbite occurs as brown pseudocubic crystals up to 0.15 mm in diameter or as colourless blades up to
about 0.5 mm long
(CM 60.787-795).
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