Anthophyllite

Forms a series with ferro-anthophyllite. May be easily confused with proto-anthophyllite.

History

Activities related to discovery and approval of the group members

Structural context

Anthophyllite
Crystal System orthorhombicCrystal Class orthorhombic dipyramidalSpace Group Pnma
a18.5—18.634 (18.5732)
b17.89999—18.136 (18.0254)
c5.27—5.313 (5.2898)
alpha90
beta90
gamma90
volume1745.16—1793.4 (1771.0385)

Based on 10 measurements

Chemical context

Stoichiometric formulas

Anthophyllite
mindat.org
  • March 13, 2023◻{Mg2}{Mg5}(Si8O22)(OH)2The anthophyllite group are orthorhombic amphiboles in the magnesium-iron-manganese amphibole subgroup. The minerals in this root name group may have either Pnma or Pnmn (proto- prefixed name) space-group symmetry. The anthophyllite group's composition is defined with A(Na+K+2Ca)<0.5 apfu and C(Al+Fe3++2Ti)<1 apfu. Anthophyllite has a standard Pnma space-group symmetry and is defined with Mg as the dominant element both in the B and C positions.
IMA
  • March 13, 2023◻Mg2Mg5Si8O22(OH)2
mineralogy.rocks
  • Aug. 30, 2022[box]Mg2Mg5Si8O22(OH)2

Elements recorded on EPMA

9
Mg
9
O
9
Si
8
H
7
Fe
1
Al
1
Ca
1
Mn
1
Na

Physical properties

ColorColor entities, recognized using a custom trained NER model
    • greenish grey
    • brownish green
    • clove brown
    Color noteOriginal color note from the source
    White, greenish grey, green, clove brown, or brownish green
    StreakStreak entities, recognized using a custom trained NER model
    • greyish-white
    Streak noteOriginal streak note from the source
    White to greyish-white.
    Lustre
    Vitreous
    Pearly
    Fracture
    Conchoidal
    Transparency
    Transparent
    Translucent
    Luminescence
    Nonfluorescent
    Hardness
    5.5—6
    Measured density
    2.85—3.57
    Calculated density
    3.67