Posnjakite

Formula: Cu4(SO4)(OH)6.H2O

Origin of name: for E. Posnjak, Russian-American geochemist

 

Crystal system: monoclinic

Crystal class: m

Twinning: 

Unit cell: a = 14.24 Å, b = 6.34 Å, c = 10.57 Å, b = 102.9°

 

Colour: blue to dark blue

Diaphaneity: 

Luster: vitreous

Habit: crystals tabular, to 0.2 to 0.5 mm, small grains, thin films

Hardness: 2 to 3

Specific gravity: 3.35

Cleavage: none

Tenacity: 

Streak: bluish

 

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