Sapphires and Rubies Are Made From This Mineral
This page is the CodyCross answer for the clue below from Mexico, Group 1366, Puzzle 1 (Vicente Guerrero).
Question is: Sapphires and Rubies Are Made From This Mineral
and the answer is: CORUNDUM
Word Meaning:
CORUNDUM — (mineralogy) An extremely hard mineral, a form of aluminum oxide with the chemical formula Al₂O₃, that occurs in the form of the gemstones sapphire and ruby; it is used as an abrasive.
Definitions from Wiktionary.