:Spray of thin, tabular crystals of onoratoite. At the bottom left a clear and well-formed crystal of gypsum. This is an old specimen, already represented in the book "Come collezionare i minerali dalla A alla Z", Alberto Peruzzo Editore, 1988, page 221. Ex A. & R. Pagano collection. Now in the collection of Gianfranco Ciccolini, author of the photo here posted. Locality: Le Cetine di Cotorniano Mine, Chiusdino, Siena Province, Tuscany, Italy — Photo: Gianfranco Ciccolini · CC0
Onoratoite
Onoratoite is an IMA-recognized mineral species in the halide class, with the chemical formula Sb₈O₁₁Cl₂.
It crystallizes in the monoclinic crystal system (space group C2/m).
Key properties: specific gravity 5.3; optically biaxial.
IMA symbol Ono, IMA status: approved, named in 1967.
An oxidation product of stibnite in an antimony deposit in highly silicified evaporites.
It is found associated with Stibnite, stibiconite, cetineite, peretaite, klebelsbergite, quartz.
The mineral was named to honor Ettore Onorato (1899–1971), Italian mineralogist.