corundum
UK[kəˈrʌn.dəm]US[kəˈrʌn.dəm]
n
a very hard mineral consisting of aluminum oxide, used as an abrasive and as a gemstone in its colored forms (such as ruby and sapphire).
Etymology
the term 'corundum' entered english in the early 18th century from the tamil word 'kuruntam', which itself likely derives from the sanskrit 'kuruvinda', meaning 'ruby'. this journey from ancient indian languages into modern mineralogy illustrates the trade and cultural exchange that brought precious stones and their names to the west. the word was adopted into scientific vocabulary to classify a specific crystalline form of aluminum oxide, distinguishing it from other hard minerals. its persistence in english reflects the substance's enduring industrial and gemological importance.
Analysis
the word is a simplex loanword. it is not productively formed from separable english morphemes.
Examples
sapphires and rubies are both varieties of the mineral corundum.
due to its extreme hardness, corundum is often used in grinding wheels and sandpaper.
the geologist identified the transparent crystal as pure corundum.