Constituent
Name
Calcium amphibole
IMA name
Calcium Amphibole Subgroup
Class
silicate mineral
Compound type
inosilicate
Relevance
main - major
Arrangement
single phase
Mass fraction
1.0
Formula
Na01Ca2((Mg2+,Fe2+)5m(Al,Fe3+,Ti)m)(Si8(n+m)Al(n+m))O22(OH,F)2 \ \ \ \ \ with m = 0, 1, 2
Chemical formula
(Na)0-1Ca2(Mg,Fe,Al,Ti)5(Si,Al)8O22(OH,F)2
Elemental formula
(Ca)2-3 (Na+)0-1 (Mg2+)0-5 (Fe2+)0-5 (Al3+)0-5 (Fe3+)0-2 (Ti4+)0-1 (Si)5-8 O22 (F)0-2 (H)0-2 (O-)0-2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
Ca Calcium element 2 - 3 constituent element main
Na+ Sodium cation element 0 - 1 constituent element main
Mg2+ Magnesium(II) cation element 0 - 5 constituent element main
Fe2+ Iron(II) cation element 0 - 5 constituent element main
Al3+ Aluminium(III) cation element 0 - 5 constituent element main
Fe3+ Iron(III) cation element 0 - 2 constituent element main
Ti4+ Titanium(IV) cation element 0 - 1 constituent element main
Si Silicon element 5 - 8 constituent element main
O Oxygen element 22 constituent element main
F Fluorine element 0 - 2 constituent element main
(OH) Hydroxide anion chemical function 0 - 2 anionic radical main
Composition comments
with Mg+Fe+Mn+Li < 1.5, and Ca+Na ≥ 1.00 and Na < 0.50 -- K+, (and Ba2+, Sr2+, Ca2+, Li+) can replace Na+; Na+, Mg2+, Fe2+, Mn2+, Li+ (and Sr2+, Ba2+, Mn2+, Fe2+, Co2+, Ni2+, Zn2+, Mg2+, Pb2+, Cu, Zr, Mn3+, Cr3+, V, Fe3+) can partly replace Ca2+; Mn2+, Li+, Zn2+, Ni2+, Co2+, Fe3+, V, Cr3+, Mn3+, Zr can partly replace (Mg,Fe,Al,Ti); Ti can partly replace (Si,Al); Cl, O can partly replace (OH,F)
Chemical functions
  Function Number
(OH)
Chemical bonds
  Bond Number
OH 1
Oxides
Formula CaO Na2O MgO FeO Fe2O3 Al2O3 TiO2 SiO2 F H2O
Mass fraction (%)

Strunz

Class
silicates (09)
Division
inosilicate (09.D)
Family
with 2-periodic double chains, Si4O11; Clinoamphiboles (09.DE)

Dana

Major class
silicates (VIII)
Class
inosilicate double-width unbranched chains, w=2 (66)
Type
with P=2 amphibole configuration (66.01)
Group
group 2, the calcic amphiboles (66.01.03a)
Phase type
crystalline
Crystal system
monoclinic
Crystal class
prismatic
Crystal class symbol
2/m (C2h)
Crystal spacegroup
C2/m
Texture
monocrystalline
Refringence type
biaxial