Gysinite-(Ce)

gysinite-(Ce)

cerium

albite

mimetite

Images

Formula: PbCe(CO3)2(OH)(H2O)
Hydrated carbonate, ancylite group, ancylite supergroup, cerium-bearing mineral
Crystal System: Orthorhombic
Specific gravity: 5.136 calculated for the empirical formula
Hardness: 3½
Streak: Pale yellow
Colour: Brownish-yellow
Luminescence: Does not fluoresce under long wave or short wave UV
Solubility: Soluble with effervescence in room-temperature dilute hydrochloric acid
Environments

Hydrothermal environments

Gysinite-(Ce) is a new mineral, approved in 2023 and to date (January 2025) reported only from the type locality.

Localities

At the type locality, the Abendröthe Mine, St Andreasberg, Braunlage, Goslar District, Lower Saxony, Germany, gysinite-(Ce) was found. The mines of St Andreasberg exploited lead - copper - silver - arsenic veins emplaced by hydrothermal solutions in a complex system of fractures. The ores were concentrated by descending waters, which resulted in oxidation-zone mineralisation. The only known crystals of gysinite-(Ce) occur in a single vug in association with albite, calcite and mimetite. Gysinite-(Ce) is a secondary oxidation zone mineral. It occurs in intergrowths of equant pseudo-octahedral crystals, up to about 0.7 mm in maximum dimension. Crystal faces tend to be irregular and somewhat rounded. The mineral is brownish yellow with a pale yellow streak. The lustre is vitreous to subadamantine, the tenacity is brittle and the fracture is curved and irregular (CJMP 62.863-870).
Gysinite-(Ce) from the Abendröthe Mine - Image

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