Asbestos () is a naturally occurring fibrous silicate mineral. There are six types, all of which are composed of long and thin fibrous crystals, each fibre being composed of many microscopic "fibrils" that can be released into the atmosphere by abrasion and other processes. Inhalation of asbestos fibres can lead to various dangerous lung conditions, including mesothelioma, asbestosis, and lung cancer, so it is now notorious as a serious health and safety hazard. Archaeological studies have found evidence of asbestos being used as far back as the Stone Age to strengthen ceramic pots, but large-scale mining began at the end of the 19th century when manufacturers and builders began using asbestos for its desirable physical properties. Asbestos is an excellent electrical insulator and is highly fire-resistant, so for much of the 20th century it was very commonly used across the world as a building material, until its adverse effects on human health were more widely acknowledged in the 1970s. Many modern buildings constructed before the 1980s are thought to contain asbestos. The use of asbestos for construction and fireproofing has been made illegal in many countries. Despite this, at least 100,000 people are thought to die each year from diseases related to asbestos exposure. In part, this is because many older buildings still contain asbestos; in addition, the consequences of exposure can take decades to arise. The most common diseases associated with chronic asbestos exposure are asbestosis (scarring of the lungs due to asbestos inhalation) and mesothelioma (a type of cancer). Many developing countries still support the use of asbestos as a building material, and mining of asbestos is ongoing, with the top producer, Russia, having an estimated production of 790,000 tonnes in 2020. Etymology The word "asbestos", first used in the 1600s, ultimately derives from the , meaning "unquenchable" or "inextinguishable". The name reflects use of the substance for wicks that would never burn up. It was adopted into English via the Old French abestos, which in turn got the word from Greek via Latin, but in the original Greek, it actually referred to quicklime. It is said by the Oxford English Dictionary to have been wrongly used by Pliny for asbestos, who popularized the misnomer. Asbestos was referred to in Greek as amiantos, meaning "undefiled", because it was not marked when thrown into a fire. This is the source for the word for asbestos in many languages, such