Anthophyllite is an orthorhombic amphibole mineral that is formed when magnesium-rich rocks, like impure dolomitic shales and ultrabasic igneous rocks, undergo metamorphism.

Some forms of anthophyllite are lamellar or fibrous and are classed as asbestos.

Anthophyllite was used as a fire retardant in ships and as insulation against seawater corrosion.

Exposure to anthophyllite asbestos can cause disease, including lung cancer, asbestosis, and mesothelioma. The severity of the lung reaction is correlated with the duration and intensity of exposure.