Bentonite

Part of speech: noun

Definitions

1. A naturally occurring clay mineral that is mainly comprised of montmorillonite and is renowned for its swelling properties when exposed to water
2. This type of clay is primarily derived from volcanic ash and is widely utilized in industries such as drilling, construction, and environmental remediation
3. A type of absorbent clay formed primarily from volcanic ash that expands when wet

Etymology: Bentonite takes its name from a place rather than a person or a process. The clay was first mined near Fort Benton in Montana, and geologists named the material after that locality, with the Greek-derived suffix "-ite" that mineralogists routinely attach to rock and mineral names. The result is a word built from a town name plus a mineral-naming ending, so the name records where the material was found rather than what it does. The clay itself is a product of volcanic ash that has been altered over long spans of time. Its usefulness comes from its structure: it swells considerably when it takes up water and can soak up large quantities of liquid, which is why it became valuable in drilling muds, pet litter, and as an absorbent in many other applications. The name, though, says nothing about these properties. It simply marks the spot where it was first found.