Intercalation is a general term to describe the movement of atoms, ions or molecules into a layered host structure, often a swelling clay mineral. This process can be reversible or non-reversible. The host-structure layers are essentially unchanged with the inserted material going between the layers. The layers must remain semi-contiguous via stacking. Intercalation commonly involves cation exchange or solvation reactions. Intercalation may involve, for example, H₂O molecules or surfactants of single planes (monolayers) to paraffin-type layers between the layers of the host phase. The resulting structure is an “intercalated structure”.
See delamination, exfoliation. (From AIPEA Nomenclature Committee, 2011, unpublished)

In optical crystallography, an interference color results with crossed polarizers where light enters an appropriately crystalline medium and refracts (separates into two ray fronts); thus, each wave front travels at slightly different velocities with a change in both speed and direction. Upon leaving the medium, the wave fronts interfere (recombine) and produces a component of light where there is a difference, or retardation, between the two wave fronts. This difference results in a change in wavelength in the final wave front, which produces a change in color, called an interference color.

A general term that implies either the region between the two adjacent layers or the relation between the two adjacent layers (quot Guggenheim et al., 2009). “Interlayer distance” is more precise to describe the distance between the adjacent layers (tetrahedral sheet to tetrahedral sheet, as shown in Fig. 2), and is measured by taking the average of the z coordinate of the basal oxygen plane. The “interlayer displacement” describes the displacement portion or lateral shift from tetrahedral sheet to tetrahedral sheet across the interlayer space. Cf., layer, layer displacement

A general term that implies either the region between the two adjacent layers or the relation between the two adjacent layers (quot Guggenheim et al., 2009). “Interlayer distance” is more precise to describe the distance between the adjacent layers (tetrahedral sheet to tetrahedral sheet, as shown in Fig. 2), and is measured by taking the average of the z coordinate of the basal oxygen plane. The “interlayer displacement” describes the displacement portion or lateral shift from tetrahedral sheet to tetrahedral sheet across the interlayer space.
Cf., layer, layer displacement

Figure 2. Illustration of terms used to describe interlayer, layers,
and intralayer topologies. From Guggenheim et al. (2009).

For phyllosilicates, interlayer material separates the 1:1 or 2:1 layers and generally may consist of cations, hydrated cations, organic material, hydroxide octahedra, hydroxide octahedral sheets (see fig. 2), and/or hydroxy-interlayers as a combination of H₂O and hydroxyl-coordinated cations. The interlayer material offsets the net negative charge of the layer. In certain cases (e.g., talc, pyrophyllite, where the net layer charge is zero), there is no interlayer material, and an interlayer separating the layers is empty. After Guggenheim et al. (2006). Cf., layer; hydroxy-interlayer

For phyllosilicates, interlayer material separates the 1:1 or 2:1 layers and generally may consist of cations, hydrated cations, organic material, hydroxide octahedra, hydroxide octahedral sheets (see fig. 2), and/or hydroxy-interlayers as a combination of H₂O and hydroxyl-coordinated cations. The interlayer material offsets the net negative charge of the layer. In certain cases (e.g., talc, pyrophyllite, where the net layer charge is zero), there is no interlayer material, and an interlayer separating the layers is empty. After Guggenheim et al. (2006).
Cf., layer; hydroxy-interlayer

For phyllosilicates, interlayer material separates the 1:1 or 2:1 layers and generally may consist of cations, hydrated cations, organic material, hydroxide octahedra, and/or hydroxide octahedral sheets (see fig. 2). The interlayer material offsets the net negative charge of the layer. In certain cases (e.g., talc, pyrophyllite, where the net layer charge is zero), there is no interlayer material, and an interlayer separating the layers is empty. After Guggenheim et al. (2006).
Cf., layer

abbreviated from interlayer-cation-deficient mica (Rieder et al., 1998). A group name for platy phyllosilicates of 2:1 layer and a layer charge of between -0.6 to -0.85 per formula unit. Interlayer-deficient micas do not have swelling capacity. The subgroups of the brittle micas are based on dioctahedral or trioctahedral character (wonesite is the only known member of the trioctahedral subgroup), and species within the subgroups are based on chemical composition. The value of -0.6 is a general limit, as wonesite appears to be an exception with a layer charge of -0.5, although it has no swelling capacity. The value of -0.85 has been fixed from examples of dioctahedral species only. Previous to Rieder et al. (1998), the term “hydromica” was used to express a perceived excess in H₂O above the O₁₀(OH)₂ formula unit, but these phases are either interstratifications (e.g., hydrobiotite = interstratification of biotite and vermiculite) or micas that exhibit a deficiency in interlayer cation occupancy. Thus, the term “hydromica” was abandoned in favor of interlayer-deficient mica. The term for species “hydrobiotite” was confusing, and the use of the prefix “hydro” is now avoided. Cf., mica, true mica, brittle mica, group names

Abbreviated from interlayer-cation-deficient mica (Rieder et al., 1998). A group name for platy phyllosilicates of 2:1 layer and a layer charge of between -0.6 to -0.85 per formula unit. Interlayer-deficient micas do not have swelling capacity. The subgroups of the brittle micas are based on dioctahedral or trioctahedral character (wonesite is the only known member of the trioctahedral subgroup), and species within the subgroups are based on chemical composition. The value of -0.6 is a general limit, as wonesite appears to be an exception with a layer charge of -0.5, although it has no swelling capacity. The value of -0.85 has been fixed from examples of dioctahedral species only. Previous to Rieder et al. (1998), the term “hydromica” was used to express a perceived excess in H₂O above the O₁₀(OH)₂ formula unit, but these phases are either interstratifications (e.g., hydrobiotite = interstratification of biotite and vermiculite) or micas that exhibit a deficiency in interlayer cation occupancy. Thus, the term “hydromica” was abandoned in favor of interlayer-deficient mica. The term for species “hydrobiotite” was confusing, and the use of the prefix “hydro” is now avoided.
Cf., mica, true mica, brittle mica, group names

a concept introduced by Nadeau et al. (1984) which theorizes that individual clay mineral particles of oriented samples used in X-ray diffraction studies are stacked in aggregated composite particles which coherently scatter radiation so as to give rise to 00l diffraction patterns similar to those of uncleaved McEwan crystallites. The composite particles are theorized to be produced during sample preparation following disaggregation of original rock or soil samples.