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Borate

Peprossiite-(Ce)

(Ce,La)(Al₃O)₂/₃B₄O₁₀
Hardness2
Crystal systemHexagonal
ClassBorate
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Peprossiite-(Ce)

Peprossiite-(Ce) is an IMA-recognized mineral species in the borate class, with the chemical formula (Ce,La)(Al₃O)₂/₃B₄O₁₀.

It crystallizes in the hexagonal crystal system (space group P-62m).

Key properties: Mohs hardness 2; specific gravity 3.45; White streak; Vitreous luster; optically uniaxial.

IMA symbol Pep-Ce, IMA status: approved, named in 1990.

A very rare mineral, formed in cavities in sanidine ejecta by circulation of pneumatolytic to hydrothermal fluids, probably above 350 ° C (Monte Cavalluccio, Italy).

It is found associated with Sanidine, aegirine–augite, hellandite, zircon, titanite, magnetite (Monte Cavalluccio, Italy).

The mineral was named to honor Giuseppe (“Pep”) Rossi (1938–1989), mineralogist and crystallographer, University of Pavia, Pavia, Italy.

Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet. Browse more P minerals or help write this entry.