Coffinite; Posey Mine, Utah, USA; 1 flat; unique
This flat contains a selection of differently sized specimens displaying the typical grey to grey-brown appearance of Coffinite. The pieces are predominantly fine-grained to massive with a dull lustre, representing the characteristic habit of this rare uranium mineral from the Posey Mine. Each specimen differs in shape, size and texture, making the flat a varied and distinctive collector's lot.
Geology & Locality
The Posey Mine in the Red Canyon District of Utah is one of the classic uranium-vanadium deposits of the Colorado Plateau. Coffinite formed there as a uranium-bearing silicate through hydrothermal processes and the redistribution of uranium-rich solutions within the sandstone-hosted ore bodies. The mine is internationally recognised for its rare uranium minerals and remains an important locality for specialised mineral collections.
Abbreviations commonly used in mineralogy.
| Abbreviation | Meaning |
| xl | single crystal, possible with matrix |
| xls | noticeable crystals |
| (xl) | embedded or damaged |
| (xls) | embedded or damaged |
| MASS | massive and/or amorphous pieces |
| TYP | type locality of the original description |
| SWUV | shortwave-UV-reaction |
| UV | ultraviolet reaction |
| SC | self-collected |
| U | unique (single unique piece) |