Mineral phase
- IMA name
- Saponite-Hectorite-Sauconite series
- Secondary names
- Trioctahedral Smectites series
- Class
- silicate mineral
- Compound type
- phyllosilicate
- Formula
- $(Ca_{0.5},Na_{0.3})(Mg,Li,Fe,Al)_3.(Si,Al)_4O_{10}(OH)_2 \bullet n(H_2O)$
- Chemical formula
- [Na(1-x)Ca0.5(1+x)]0.3[(Mg)x(Fe2+)y(Li)z(Zn)1-x-y-z]3[(Si)x(Al)1-x]4O10(OH)2•n(H2O)
- Elemental formula
- (Na)0-0.5 (Ca)0-0.15 (Mg)0-3 (Fe2+)0-1 (Li)0-0.5 (Zn)0-3 (Al)0-1.5 (Si)2.5-4 O12 H2
- Isotope mixture type
- terrestrial abundance
- Composition comments
- Partial solid solution - Common impurities: Ti, Mn, Cu, Ni, K, P, Cl
- Oxides
-
Formula $Na_{2}O$ $CaO$ $MgO$ $FeO$ $Li_{2}O$ $ZnO$ $Al_{2}O_{3}$ $SiO_{2}$ $H_{2}O$ Mass fraction (%)
Strunz
- Class
- silicates (09)
- Division
- phyllosilicate (09.E)
- Family
- Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets (09.EC)
- Code
- 09.EC.45
Dana
- Major class
- silicates (VIII)
- Class
- phyllosilicate sheets of six-membered rings (71)
- Type
- with 2:1 clays (71.03)
- Group
- Smectite group (Trioctahedral Smectites) (71.03.01b)
- Phase type
- crystalline
- Crystal system
- monoclinic
- Crystal class
- prismatic
- Crystal class symbol
- 2/m (C2h)
- Crystal spacegroup
- C2/m
- Molar mass
- 383.25 - 580.37 $g/mol$
- Density
- 2.0 - 3.0 $g/cm^3$
- State NTP
- solid
- Refringence type
- biaxial
- Refringence sign
- negative
- Birefringence
- 0.030 - 0.040
- Refraction index $n_{\alpha}$
- 1.479 - 1.58
- Refraction index $n_{\beta}$
- 1.50 - 1.62
- Refraction index $n_{\gamma}$
- 1.511 - 1.62
- Pure color
- white
- Diaphaneity
- translucent to opaque
- Luster
- earthy