Pyrochroite

Formula: Mn(OH)2

Origin of name: from Greek for fire and colour

 

Crystal system: hexagonal

Crystal class: -3 2/m

Twinning: 

Unit cell: a = 3.32 Å, c = 4.74 Å

 

Colour: colourless, white, pale green, blue, becomes dark brown then black

Diaphaneity: becomes opaque on exposure

Luster: pearly on cleavage when fresh

Habit: crystals tabular, rhombohedral, rarely prismatic, massive, foliated, thin veinlets

Hardness: 2.5

Specific gravity: 3.25

Cleavage: 1; {0001} perfect

Tenacity: thin foliae flexible

Streak: 

 

Synonyms/varieties:

 

Comments: 

 

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