Cashmere wool, usually simply known as cashmere, is a fiber obtained from cashmere goats or pashmina goats and other types of goat. It has been used to make yarn, textiles and clothing for hundreds of years. The word cashmere is an anglicisation of Kashmir.

Common usage defines the fiber as wool, but it is finer, stronger, lighter, softer and approximately three times more insulating than sheep wool. Both the soft undercoat and the guard hairs may be used; the softer hair is reserved for textiles, while the coarse guard hair is used for brushes and other non-apparel purposes. A number of countries produce cashmere and have improved processing techniques over the years, but China and Mongolia are two of the leading producers as of 2019.

High demand for the valuable fiber has resulted in the decimation and transformation of grasslands into deserts in Asia, increasing local temperatures and causing air pollution which has traveled to the Americas. Also, some yarns and clothing marketed as containing cashmere have been found to contain little to no cashmere fiber, so more stringent testing has been requested to make sure items are fairly represented.

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