Tenacity
Definition
The resistance of a mineral to breaking, bending, or deforming. Terms like brittle, sectile, malleable, and elastic describe a mineral's tenacity.
Example
Copper is malleable, meaning it can be hammered into thin sheets, while quartz is brittle and shatters easily.
How Does It Deform?
While <strong>hardness</strong> measures resistance to scratching, <strong>tenacity</strong> measures how a mineral reacts to stress like crushing, bending, or tearing. It describes the mechanical behavior of the material. This is a key test for distinguishing real gold from look-alikes.
Terms of Tenacity
- Brittle: Breaks or powders when hammered (e.g., Quartz, Pyrite). "Fool's Gold" shatters; real Gold flattens.
- Malleable: Can be hammered into thin sheets without breaking (e.g., Gold, Copper).
- Sectile: Can be cut smoothly with a knife like hard cheese (e.g., Gypsum, Gold).
- Elastic: Bends and snaps back to its original shape (e.g., Mica sheets).
- Flexible: Bends but stays bent (e.g., Copper wire).