Mineral Hardness Identification Guide
Identify minerals by Mohs hardness, streak color, and luster.
Includes common hardness reference objects.
Mineral Matches
Mohs Hardness Scale Developed by Friedrich Mohs in 1812, this scale ranks minerals from 1 (softest) to 10 (hardest) based on scratch resistance. A mineral can scratch anything softer than itself.
Common Reference Objects Fingernail ≈ 2.5, Copper coin ≈ 3.0, Iron nail ≈ 4.0, Glass plate ≈ 5.5, Steel file ≈ 6.5.
Streak Test The streak is the colour of a mineral’s powder, often different from the mineral surface colour. It is tested by scratching the mineral across an unglazed porcelain tile.
Luster Luster describes how light reflects from the mineral surface — metallic, glassy (vitreous), pearly, silky, or dull.