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Bradaczekite, (w. Koritnigite)


Chemistry: NaCu4(AsO4)3
Size: FOV 25 mm
Owner: W.W. (Bill) Pinch
Photographer: Jeff Scovil

Waxy blue aggregates of poorly crystalline bradaczekite, as inclusions in, and intergrowths with, a green amorphous phase similar to the material designated as "GS1" by Gebhard (1999). XRD analysis at ambient temperature shows this green material to be amorphous, while microprobe analysis indicates that it is chemically equivalent to koritnigite; on heating, however, a koritnigite powder pattern is obtained.  

XRD analysis has confirmed that the minor, white, crystalline phase (at upper left of centre) is koritnigite, while the paler, slightly turquoise-blue cleavages at upper left and upper right of the photograph are andyrobertsite.

The specimen is believed to be from the third oxidation zone.