Constituent
- Name
- smectites
- IMA name
- Smectites
- Class
- silicate mineral
- Compound type
- phyllosilicate
- Comments
- Monoclinic clay-like minerals
- Relevance
- main - major
- Arrangement
- homogeneous in multi-phases
- Formula
- $A_{0.3}D_{2-3}.(T_4O_{10})Z_2 \bullet n(H_2O)$
- Chemical formula
- A0.3D(2-3)T4O10Z2•n(H2O)
- Isotope mixture type
- terrestrial abundance
- Composition comments
- A=Na,Ca,Li; D=Mg,Fe2+,Fe3+,Al,Li,Ni,Zn,Cr,Cu; T=Si,Al; Z=OH,F - Common impurities: Ti, K
Strunz
- Class
- silicates (09)
- Division
- phyllosilicate (09.E)
- Family
- Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets (09.EC)
Dana
- Major class
- silicates (VIII)
- Class
- phyllosilicate sheets of six-membered rings (71)
- Type
- with 2:1 clays (71.03)
- Group
- N/A (N/A)
- Phase type
- crystalline
- Crystal system
- monoclinic
- Crystal class
- prismatic
- Crystal class symbol
- 2/m (C2h)
- Crystal spacegroup
- C2/m
- Texture
- polycrystalline
- Molar mass
- 383.25 - 580.37 $g/mol$
- Density
- 2.0 - 3.0 $g/cm^3$
- Refringence type
- biaxial
- Refringence sign
- negative
- Birefringence
- 0.015 - 0.040
- Refraction index $n_{\alpha}$
- 1.479 - 1.58
- Dispersion V
- none to strong
- Diaphaneity
- translucent to opaque
- Luster
- earthy