Gemstone hardness is most often measured on which scale?

• A. Mohs scale
• B. Vickers scale
• C. Beaufort scale
• D. Richter scale

Answer: (A)

Hardness testing in gemology focuses on a mineral’s resistance to scratching. The most practical and widely used system is a relative set of reference minerals that show which substances can scratch others. The Mohs scale does exactly this: it ranks ten minerals from softest to hardest and uses simple scratch tests to determine where a gem sits on that spectrum. This approach is intuitive for identifying and comparing gemstones in everyday practice, and it correlates well with how durable a stone will be in setting and wear. It also provides a consistent framework that professionals around the world recognize, making it the standard tool for describing gemstone hardness.

Other options aren’t used for gemstone hardness in the same way. The Vickers scale measures hardness by indenting a material with a diamond pyramid and is a precise laboratory test suited for metals and ceramics, not for quick gem assessment. The Beaufort scale describes wind force, and the Richter (or moment magnitude) scale measures earthquake size.