« Back to Glossary IndexRefractory Ceramic Fibres : fiber up to 1426 °C (2600 °F) , MMVF whose chemical constituents are predominantly alumina and silica ,RCFs are amorphous fibers used for high-temperature insulation applications. RCFs are less durable/biopersistent than amphibole asbestos, but more durable/biopersistent than many other synthetic vitreous fibers