Crocidolite asbestos, which is also commonly referred to as “blue” asbestos, belongs to the amphibole family of asbestos types. As such, it is quite finely textured and looks very much like human hair. Its color ranges from a dull slate gray to a very vibrant dark blue. The fibers of crocidolite are fairly flexible, able to bend to about 90 degrees before breaking.
Crocidolite occurs in naturally-formed bundles that are long, sharp, and straight. This makes crocidolite especially easy to inhale and also makes it the most hazardous of all types of asbestos. Thankfully, it was not widely used in the United States and accounts for only about 4 percent of all the asbestos that was used in the U.S. for the manufacture of commercial products during the years before 1980.
The fact that crocidolite was not as heat resistant as other types of asbestos was one of the reasons it was far less desirable than other types of asbestos. It was also unsuitable for use in products such as insulation, which was long the primary use for asbestos. Instead, it was mostly used in the manufacture of various cement products, included to add strength and durability.
Crocidolite was never mined in the United States. Mines were generally found in Western Australia, South Africa, and Bolivia. For the most part, the mining of crocidolite had an overwhelming negative effect on those who worked in or lived near the mines. Towns like Wittenoom, Australia were great affected by the mining of crocidolite asbestos. That town has literally been wiped off the map by asbestos cancer (8 residents remain) and more than 1,000 mine workers and residents of the town have died of mesothelioma or other asbestos-caused diseases.
R. Lemen and E. Bingham, Toxicology and Industrial Health - A Case Study in Avoiding a Deadly Legacy in Developing Countries (Vol. 10, No. 1/2, Princeton Scientific Publishing Co., Inc. 1994);
H. Seidman, et al., Short-term Asbestos Work Exposure and Long-term Observation (Annals of the New York Academy of Sciences, 330:61-89, 1979).