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Ameghinite from
Tincalayu Mine, Antofagasta de la Sierra Department, Catamarca Province, Argentina


Locality type:Open-Cast Mine
Classification
Species:Ameghinite
Formula:Na(H4B3O7)
Comments:Crystals of ameghinite are characteristically elongated on <010> and flattened on {001}…On the largest crystals, about 5 millimeters long, the {001} faces are frequently curved as though bent around the a axis. The smaller crystals, one millimeter or less in length, lack the pronounced curvature but even they show some bending and give a series of signals from the {001} faces. The small crystals of ameghinite occur either partially or completely surrounded by tincalconite.

Ameghinite is also found in nodular masses embedded in massive borax. Most of them are about a centimeter in diameter, but can be up to 5 centimeters long. The manner of occurrence of ameghinite is identical with that of ezcurrite and rivadavite with which it is closely associated. In fact a single study specimen 25x15x12 centimeters contains nodules of all these minerals However unlike the other two minerals that are found in contact with the surrounding borax, the nodules of ameghinite are in every case separated from the borax by tincalconite.
Confirmation
Validity:Valid - Type Locality
Data
Mineral Data:Click here to view Ameghinite data
Locality Data:Click here to view Tincalayu Mine, Antofagasta de la Sierra Department, Catamarca Province, Argentina
Photo GalleryView Gallery (4 photos)
Data Identifiers
Mindat Occurrence Record ID:482
Long-form Identifier:1:3:482:0
GUID (UUID V4):0
References
 
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