Images
Formula: Pb1-xO3-2x(UO2)4(OH)4+2x.4H2O
Oxide, uranyl mineral
Crystal System: Orthorhombic
Specific gravity: 6.046 measured, 5.98 calculated
Hardness: 3 to 4
Streak: Orange
Colour: Red, golden-red, brown
RADIOACTIVE
Environments
Pegmatites
Sedimentary environments
Hydrothermal environments
Fourmarierite is a rare secondary mineral formed as an
alteration product of
uraninite in the oxide zone of uranium deposits; it may replace fossil
wood. Associated minerals
include uraninite, ianthinite,
schoepite, becquerelite,
billietite, dewindtite,
phosphuranylite, vandendriesscheite,
rutherfordine, torbernite,
kasolite, curite and
goethite
(HOM).
It is a common component of gummite
(Lauf2).
Localities
At Great Bear Lake, Northwest Territories, Canada, fourmarierite occurs on altered
uraninite
(Dana).
Fourmarierite from Great Bear Lake -
Image
At the type locality, the Shinkolobwe mine, Shinkolobwe, Kambove District, Haut-Katanga, DR Congo,
fourmarierite occurs with
kasolite, torbernite and other
secondary uranium
minerals
(Dana).
Fourmarierite from Shinkolobwe - Image
At Johanngeorgenstadt, Erzgebirgskreis, Saxony, Germany, Red-orange, yellow, red and orange-brown fourmarierite
occurs as an alteration product of pitchblende, and was found uncommonly,
with other hydrated uranium minerals, as crusts in oxidation zones.
(MinRec 55.5.597).
At the Monument No. 2 mine, Monument No. 2 channel, Yazzie Mesa, Cane Valley Mining District, Apache County, Arizona,
USA, fourmarierite occurs in oxidised, mineralised fossil wood
(Dana).
At Spruce Pine, Mitchell county, North Carolina, USA, fourmarierite occurs as an alteration of
uraninite in pegmatites
(Dana).
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