Serpentine Asbestos – 3cm long fibres
Once hailed as a “wonder mineral” for its fire, sound and heatproof properties, asbestos has become notorious for the terrible effects it can have on those who are exposed to it. Its long, flexible fibres can be woven into matting, mixed in with cement to make insulating boards, or teased into soft fluffy insulation. It was widely used throughout the late 19th century and most of the 20th century.
Even today, asbestos still poses a threat to health because it was used in many homes and public buildings. Fortunately, people are now aware of the risks and can use personal protective equipment when doing work like renovating and removing asbestos to avoid breathing in and touching the fibres.
Asbestos refers to a group of fibrous minerals, including “white asbestos” (chrysotile), “blue asbestos” (crocidolite) and “brown asbestos” (amosite). This sample is chrysolite, which forms in environments were ancient oceanic crust is metamorphosed and deformed. Although often much shorter, asbestos fibres can easily grow up to 3 cm long, like the ones in this specimen.
This sample of chrysotile asbestos comes from the Cassiar Asbestos mine on McDame Mountain, just north of Cassiar in northwestern BC. The mine produced asbestos from 1951 to 1989, when ore reserves were depleted. Ore from mine stockpiles continued to be processed into the early 1990s. In total, over 60 million tonnes of ore were produced there over its 40-year lifespan. More recently, there has been interest in re-opening the mine to extract magnesium, but to date this hasn’t been successful.
The Cassiar townsite is now considered a ghost town, with most houses abandoned and pulled or burned down. At its peak in the 1950s to 1970s, the population was as high as 2,500, served by local newspapers like the Asbestos Sheet.
Jade, used for jewellery and other decorative objects, was also produced at the mine.
Store: Association for Mineral Exploration (AME)
Accession #: AME 144
Primary Mineral: Asbestos
Site Locality: Mt McDame
Location: Cassiar, British Columbia
Special Features: n/a