Corundum’s "best feature" is its , ranking at a 9 on the Mohs scale. This single physical property makes it nearly indestructible in everyday wear and vital for high-tech industrial applications. Why Hardness is its Best Feature

: As the second hardest natural mineral, it is highly resistant to scratches and abrasions from almost any other material.

: This makes it the "gold standard" for jewelry intended for daily use, such as engagement rings.

: Its toughness allows it to be used in heavy-duty abrasives (like sandpaper and grinding wheels), scratch-resistant watch crystals, and even windows for spacecraft and satellites. Prominent Varieties of Corundum