chloriteserpentine

Chloriteserpentine is not a single mineral species but a term used in mineralogy and metamorphic petrology to describe a class of mixed-layer, hydrous phyllosilicates that lie between the chlorite and serpentine groups. In practice, chloriteserpentine refers to interlayered or solid-solution varieties that show structural and chemical characteristics of both chlorite-type and serpentine-type sheets, with varying proportions of each.

The composition of chloriteserpentine is highly variable, reflecting a continuum between chlorite-like and serpentine-like end members. It often forms as mosaic intergrowths or as alternating layers in which chlorite- and serpentine-like sheets share a common crystal framework. The material typically contains magnesium and iron, with aluminum and silicon distributed according to the degree of chlorite versus serpentine character. X-ray diffraction patterns are usually broad and overlapping, indicating a mixed-layer structure and variable stacking.

Formation occurs during low- to intermediate-temperature metamorphism and hydrothermal alteration of rocks rich in sheet silicates, particularly ultramafic and mafic rocks. Chloriteserpentine commonly develops in hydration zones, fault zones, and contact aureoles where fluids circulate and alter primary minerals to produce chlorite, serpentine, talc, and related phyllosilicates.

Occurrences and associations are widespread in metamorphosed rocks and ophiolites, especially in greenschist facies and zones of serpentinite alteration. The phase is of interest because it records water-rich metamorphic histories and helps interpret metamorphic grade and fluid activity. Distinctions between chloriteserpentine and the pure chlorite or serpentine end members are important in petrographic and geochemical analyses.