MOH’S HARDNESS SCALERules for testing and

identifying the hardness of minerals

How it works•Hardness is the resistance of a mineral to

scratching.•Hardness IS NOT how easily a mineral is

broken.•We determine the RELATIVE hardness of

minerals using a scale called the Moh’s hardness scale.

•The scale assigns hardness to 10 common index minerals based on their ability to scratch one another.

The Important PartMoh’s Hardness Scale Items used for testing

Hardness Index Mineral

1 Talc

2 Gypsum

3 Calcite

4 Fluorite

5 Apatite

6 Orthoclase

7 Quartz

8 Topaz

9 Corundum

10 Diamond

Hardness

Item Comments

2.5Fingerna

il

We all have 10 of these to wear out before

taking off our shoes.

3.5 PennySometimes all we have

left.

4.5 Knife

The hardness of a blade can vary wildly

depending on the quality of your knife. Check yours before

going into the field so you'll know.

5.5 GlassThere's usually a chunk

of glass available.

7 QuartzA piece of quartz can

be found almost everywhere.

1Talc

2Gypsum

2.5Fingernail

3Calcite

3.5Penny

4Fluorite

4.5Nail

5Apatite

5.5Glass

6Feldspar

6.5Steel File

7Quartz

7Streak Plate

8Topaz

9Corundum

10Diamond