Agrinierite

Agrinierite is a mineral often found in the oxidation zone of uranium deposits. It is named after Henry Agrinier (1928–1971), a french engineer for the Commissariat à l'Énergie Atomique ( Mineralogy Laboratory of the French Atomic Energy Commission, Paris, France). Agrinierite is a hydrated oxide of uranium discovered during the exploitation of the uranium deposit of Margnac (Haute-Vienne, France), the only site in the world where it is known today. It appears at the periphery of uraninite nodules accompanied by other uranium oxides which result like it from the transformation of uraninite (becquerelite, schoepite, compreignacite, rameauite, etc.). Agrinierite occurs as small tabular orange crystals, transparent to translucent, submillimeter in size, frequently twinned which gives them a pseudohexagonal appearance. ^[4]

Agrinierite [Agn]
General
Category	Mineral
Formula (repeating unit)	K2(Ca,Sr)[(UO2)3O3(OH)2]2 · 5H2O
IMA symbol	Agn[1]
Crystal system	monoclinic[2]
Identification
Color	Orange
Crystal habit	Pseudo Hexagonal - Crystals show a hexagonal outline.
Twinning	Sector twins with composition plane {110}
Cleavage	Distinct/Good on {001}
Luster	Resinous - Greasy
Diaphaneity	Transparent, Translucent
Specific gravity	5.7[3]
Density	5.62 - 5.7, Average = 5.66
Dispersion	relatively weak
Other characteristics	Radioactive