Hardness scales
We list the following 5 more accurate hardness scales that complement or exceed the Mohs scale, especially in industrial or scientific contexts where exact measurement is required:
1. Vickers Scale (HV)
What does it measure?Penetration hardness using a square pyramid-shaped diamond tip.
Applicationmetals, alloys, ceramics and thin materials.
AdvantageHardness : Provides accurate numerical values of hardness, useful for engineering purposes.
ExampleHardened steel can have a hardness of HV 600-800, while diamond can exceed HV 10,000.
2. Brinell Scale (HB)
What does it measure?Hardening by pressure by means of a steel or tungsten carbide ball on a surface.
ApplicationSoft or medium-hard metallic materials such as cast iron or aluminium.
Method: The diameter of the pressure mark is calculated after applying a standard load.
LimitationNot ideal for very hard or very thin materials.
3. Rockwell Scale (RH)
What does it measure?Depth of penetration of a diamond cone or steel ball under a fixed load.
ApplicationVery versatile: metals, plastics, even some ceramics.
Types: There are several scales (A, B, C, etc.) for different materials:
HRC: Widely used for hardened steels.
HRBFor softer materials such as brass or copper.
AdvantageIt is fast and accurate, widely used in industrial quality control.
4. Knoop Scale (HK)
What does it measure?Similar to Vickers, but with an elongated diamond tip.
Application: Very thin materials, coatings or surface coatings.
AdvantageHigh precision in small areas or microstructures.
5. Nanoindentation
What does it measure?Hardness and elastic modulus at nanometre scales.
ApplicationNanotechnology, thin films, composite materials.
MethodThe use of high-precision automated equipment that measures the response of the material when pressed by a very fine tip.
Advantage: Provides load/unload curves that provide insight into complex mechanical properties.
Quick comparison between hardness scales
| Scale | Method | Accuracy | Ideal for |
|---|---|---|---|
| Mohs | Manual scratching | Baja | Gems, minerals |
| Brinell | Penetration (ball) | Media | Soft metals |
| Rockwell | Penetration (cone/ball) | High | Metals, plastics |
| Vickers | Penetration (pyramid) | Very high | Hard metals, ceramics |
| Knoop | Penetration (micro) | Very high | Thin films, microanalysis |
| Nanoindentation | Nanoscale penetration | Extremely high | Advanced and thin materials |
Where can I find more information or practical examples?
In the world of jewellery and gemmology, many of these scales are used to validate the authenticity of gemstones and assess their resistance to wear. For example, you can visit the gemstones section of Gordillo Jewellery to see real examples of gems evaluated on the basis of their hardness and durability.
You can also explore technical and popular articles in magazines such as:
