Mondschein quarry, Rhünda, Felsberg, Schwalm-Eder, Kassel Region, Hesse, Germany

Hemispheres of orange siderite with a core of yellowish magnesite in cavity of sedimentary xenoliths in basalt. The magnesite core is visible if the outer rim of siderite is destroyed.

© Volker Betz (2021)

Branches of montmorillonite with a dark core and light outer rim in a vug of a xenolith in basaltic matrix. Such forms are sometimes found in basaltic matrix and raise the question: Are this biosignatures ? The diameter of the branches is about 50 µm and the form similar to hyphae pictured in : Ivarsson, M., Drake, H., Neubeck, A., Sallstedt, ...

© Volker Betz (2021)

Tabular prismatic, thin coated mordenite and orange siderite with clay minerals in a vug of a xenolith.

© Volker Betz (2021)

Pale violet quartz crystal aggregate with greenish pyroxene.

© Volker Betz (2021)

Lath-like, white fan of mordenite crystals with brown spheres of siderite.

© Volker Betz (2021)

Triangular, tabular crystals of tridymite arranged to a Christmans tree like aggegate on pyroxene in a vug of a xenolith.

© Volker Betz (2021)

Small, transparent crystals of siderite on a ball of magnesite. (See child picture)

© Volker Betz (2022)

Transparent rhomboherdron of siderite with a coated long prismatic crystal, most likely fluorapatite.

© Volker Betz (2022)

Branches of colorless, yellow and orange montmorillonite in a vug of a xenolith. Such forms are sometimes found in basaltic matrix and raise the question: Are this biosignatures ? The diameter of the branches is about 25 µm and the form similar to hyphae pictured in : Ivarsson, M., Drake, H., Neubeck, A., Sallstedt, T., Bengtson, S., Roberts, ...

© Volker Betz (2021)

Radiating spray of lath-like mordenite crystals, partial iron stained and with well visible terminations, in a vug of a xenolith.

© Volker Betz (2021)

View into a small vug of a xenolith with sprays of white mordenite and hemispheres of siderite.

© Voker Betz (2023)

Grey quartz crystals and orange siderite in background of a vug in a xenolith.

© Volker Betz (2021)

Long prismatic, green crystals of aegirine in a vug of a xenolith . Quartz is also present (not visible in the picture). EDX analysis by Günther Blaß.

© Volker Betz (2021)

Aggregate of yellow-orange siderite and white columnar montmorillonite aggregates in a vug of a xenolith. The montmorillonite covers possibly pyroxene.

© Volker Betz (2021)

Group of two pyrite octahedrons in parallel growth with white mordenite and yellow siderite.

© Volker Betz (2021)

Pale violet quartz crystal aggregate with greenish pyroxene.

© Volker Betz (2021)

Tabular crystals of trdymite coated with yellow colored montmrillonite.

© Volker Betz (2021)

Nice Siderite from the Rhünda quarry. Collection: Günter Blass. Photo: Fred Kruijen.

© Fred Kruijen

Hexagonal-tabular crystal of ilmenite coated with montmorillonite. Associated with coated crystals of pyroxene in a vuf of a xenolith.

© Volker Betz (2021)

Pyroxene crystal with coating and interference colours and white prismatic fluorapatite in a vug of an xenolith. The pyroxen crystals shows also oriented (epitaxial ?) intergrowth with acicular, white crystals.

© Volker Betz (2022)

Greenish, prismatic crystals of clinopyroxene with orange siderite in a vug of a xenolith.

© Volker Betz (2021)

Spindle-like quartz crystal in a vug of a xenolith.

© Volker Betz (2023)

Violet quatz crystals (amethyst) with siderite lining a vug in a xenolith.

© Volker Betz (2023)

Vug in a xenolith with balls of magnesite with a thin red coating followed by small crystals of siderite.

© Volker Betz (2022)

Octahederal pyrite crystals with reddisk coating an small mordenite crystals.

© Volker Betz (2025)