Mineral comes from Medieval Latin minerale, meaning a substance obtained by mining. The Latin word derives from minera (a mine or ore deposit), which entered Latin from Old French miniere. The deeper origin is probably Celtic — Welsh mwyn and Irish mein both mean ore or metal, and the word likely passed from Celtic-speaking populations into the French of medieval miners before Latin scholars formalized it.
In the 15th century, when English adopted the word, mineral meant anything dug from the ground: metals, ores, gemstones, salts, and earths. The classification was practical rather than scientific. If you extracted it from rock, it was a mineral. This broad usage persisted for centuries and still survives in everyday speech — people refer to mineral water, mineral supplements, and mineral rights without requiring strict geological definitions.
Modern geology narrowed the term considerably. A mineral in the scientific sense must be naturally occurring, inorganic, solid, with an ordered atomic arrangement and a definite chemical composition. This definition excludes coal (organic origin), mercury (liquid at room temperature), and synthetic diamonds (not naturally occurring), all of which earlier centuries would have called minerals without hesitation.
The nutritional use of mineral — referring to elements like iron, calcium, zinc, and potassium needed in the human diet — developed in the 19th century as chemistry identified the specific elements present in food and bodily tissue. This meaning has become dominant in popular usage, so that most people now encounter the word mineral in the context of health labels and dietary supplements rather than geology.
The related word mine, meaning an excavation site, shares the same Celtic-French root. The identical English word mine meaning belonging to me has a completely separate Germanic origin. The two words converged in spelling by accident, creating one of English's many homographic false pairs.