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💎 Mohs Hardness and Mineral Scratch Testing

Explore Friedrich Mohs' 1812 ordinal hardness scale through an interactive scratch-test simulator. Rank ten reference minerals from talc to diamond, learn how the simple scratch rule works, and discover why the scale is relative rather than proportional.

Geology & Earth Science3DModerate60 FPS🌍 Earth

The simulator demonstrates the pairwise scratch rule that defines Mohs hardness: selecting any two of the ten reference minerals shows which one scratches the other based on their relative hardness ranks, and a side-by-side comparison view highlights how uneven the real physical hardness gaps are between adjacent steps, especially near the top of the scale.

🔬 What It Demonstrates

🎮 How to Use

Choose two minerals from the ten Mohs reference minerals using the selectors, then run the scratch test to see which mineral marks the other and by how many hardness steps they differ. Use the everyday reference objects, fingernail, coin, knife blade, and glass, to practice bracketing an unknown sample's hardness the way a field geologist would, and toggle the Vickers comparison view to see how nonlinear the true hardness values are across the scale.

💡 Did You Know?

Diamond's real physical hardness, measured on the quantitative Vickers scale, is roughly four times greater than corundum's, even though they sit just one step apart at 10 and 9 on Mohs' ordinal scale, a vivid reminder that Mohs numbers describe order, not magnitude.

⚙ Under the hood

geologymineralogymohs scalehardnessearth sciencerocks and mineralsfield geology

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install