Formula: Mg7(Ca,Mg)(Fe,Al)2(SO4)2(OH)18.18H2O
Origin of name: locality Långban, Bergslagen ore district, Filipstad, Wermland (Värmland), Sweden
Crystal system: Trigonal
Crystal class: 3 2/m
Twinning:
Unit cell: a = 9.26 Å, c = 22.52 Å
Colour: Greenish gray, bluish
Diaphaneity: Semitransparent
Luster:
Habit: Crystals platy, thin hexagonal
Hardness: 1.5
Specific gravity: 1.93
Cleavage: 1; {0001} perfect
Tenacity: Micaceous fracture, flexible but inelastic
Streak:
Synonyms/varieties:
Comments:
| Back to Alphabetical list | Colour photos | Optical properties/Thin sections | SEM images | TEM images | vibrational spectra description | IR spectra | Raman spectra | N-IR spectra | F-IR spectra | IES spectra |