Povondraite

Formula: NaFe3Fe6(BO3)3(Si6O18)(O,OH)4

Origin of name: for Pavel Povondra, Czech geochemist

 

Crystal system: hexagonal

Crystal class: 3m

Twinning: 

Unit cell: 

 

Colour: black

Diaphaneity: 

Luster: resinous

Habit: crystals malformed, nearly equant habit, in subparallel aggregates

Hardness: 7

Specific gravity: 3.26

Cleavage: none

Tenacity: 

Streak: brown

 

Synonyms/varieties:

 

Comments: povondraite is a redefinition of ferridravite

 

Back to Alphabetical list Colour photos Thin sections SEM images TEM images vibrational spectra description IR spectra Raman spectra N-IR spectra F-IR spectra IES spectra