Fibrous
The Workers' Compensation Board of British Columbia definition of a fibre is
FIBROUS (National Research Council, 1984) refers to “(1) single crystals that resemble organic fibers such as hair orcotton and (2) large crystals or crystalline aggregates that look like they are composed of fibers (i.e., long, thin, needlelikeelements) (Dana and Ford, 1932). The apparent fibers do not need to be separable. If the fibers are separable and are strongand flexible, they are asbestiform. If they have the normal strength and brittleness of the mineral, they are acicular.” Theterms “apparently fibrous” or “pseudofibrous” are sometimes applied to single crystals or polycrystalline aggregates thathave a fibrous appearance but are not composed of separable fibers. In such cases, the fibrous appearance may be the resultof oscillatory crystal growth, twinning, or pseudomorphic replacement of another fibrous mineral.
ASBESTIFORM (National Research Council, 1984) refers to “the unusual crystallization habit of a mineral when thecrystals are thin, hair like fibers. Historically, the definition of asbestiform habit was based primarily on appearance, and theproperties were only implied. At present, the definition of asbestiform habit is often augmented to include a statement on theproperties of asbestiform fibers, i.e., shape; enhanced strength, flexibility, and durability; diameter-dependent strength; andunique surfaces. The fibers of asbestos are good examples of the asbestiform habit.” In these guidelines, “asbestiform”refers to the crystallization habit of a mineral where the crystals are thin, hair like fibers, with unique properties asmentioned above. The term “fibrous” is a broad term that refers to fibrous appearing crystals without any implicationregarding the special properties implied by the term asbestiform. Asbestiform describes a special type of fibrosity.Asbestiform minerals are fibrous but not all fibrous minerals are asbestiform.