Mica

Mica is a group of sheet silicate minerals that cleave into thin, flexible layers. Its heat resistance and electrical insulating properties make it useful in industry and technology.

Phyllosilicate: A silicate mineral whose structure consists of sheets of linked silicon-oxygen tetrahedra. Mica belongs to this mineral class, whose sheet structure accounts for its easy splitting.
Dielectric: An electrical insulator that can be polarized by an applied electric field. Mica acts as a dielectric in capacitors and other electrical components.
Tetrahedral-octahedral-tetrahedral layer: A sheet-silicate structural unit with an octahedral sheet sandwiched between two tetrahedral sheets. Mica’s characteristic layers have this three-sheet arrangement.
Biotite: A dark, iron- and magnesium-rich mica common in igneous and metamorphic rocks. Biotite is a widespread mica species whose composition makes it dark and readily altered.
Child labour: Work that deprives children of childhood, education, or healthy development, or harms their well-being. Reports of child labor in parts of the mica supply chain have prompted scrutiny and reform efforts.
Silicate mineral: A mineral built from silicon-oxygen units combined with other elements. Mica’s chemistry and crystal structure place it among silicate minerals.
Electrical insulation: Materials or structures that impede the flow of electric current. Mica’s insulating sheets separate conductors in equipment exposed to heat.
Isomorphous substitution: The replacement of one ion by another of similar size within a crystal structure. Substitutions within mica layers create charge that is balanced by interlayer cations.
Lepidolite: A lithium-rich mica, often pink or lilac, found chiefly in granitic pegmatites. Lepidolite demonstrates how mica structures can host lithium.
Responsible sourcing: Procurement practices that assess and address social and environmental risks in supply chains. Mica buyers use traceability and supplier standards to address mining-related risks.

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