Schaurteite, Ca(3)Ge(SO(4))(2)(OH)(6)·3H(2)O.

Area of Science:

• Mineralogy
• Crystallography
• Geochemistry

Background:

• Schaurteite (Ca(3)Ge(SO(4))(2)(OH)(6)·3H(2)O) is a rare mineral belonging to the fleischerite group.
• Understanding its crystal structure is crucial for mineral classification and understanding related compounds.

Purpose of the Study:

• To determine the first crystal structure of schaurteite using single-crystal X-ray diffraction.
• To elucidate the atomic arrangement and bonding within the schaurteite mineral structure.

Main Methods:

• Single-crystal X-ray diffraction was performed on a natural schaurteite sample.
• Full-matrix refinement was employed to locate atoms and hydrogen bonds within the crystal structure.

Main Results:

• The crystal structure of schaurteite was successfully determined, revealing its unique composition: tricalcium germanium bis-(sulfate) hexa-hydroxide trihydrate.
• The structure features slabs of calcium polyhedra interleaved with germanium octahedra and sulfate tetrahedra.
• Two hydrogen atoms were located, participating in O-H⋯O hydrogen bonds.

Conclusions:

• This study provides the definitive crystal structure of schaurteite, a significant contribution to mineralogy.
• The determined structure clarifies schaurteite's relationship within the fleischerite group of minerals.
• The findings offer insights into the structural chemistry of germanium-bearing minerals.