ROCKS AND MINERALS

 

Did you know that the hardness of rocks and minerals is measured on a scale called

MOHS' HARDNESS SCALE

This shows that the hardness of minerals ranges from 1 - 10.

The softest is shown with a hardness of 1 - the hardest is 10.

Your fingernail has a hardness of about 2.5 and a knife blade is about 5.5.

 

MOHS' HARDNESS SCALE

Hardness Scale Mineral Hardness Test
     

1.
 Talc Talc is the softest mineral and can be scratched by your fingernail.

2.
 Gypsum  

3.
 Calcite Calcite can be scratched with a copper coin.

4.
 Fluorite Fluorite can be scratched by a knife blade or window glass.

5.
 Apatite  

6.
 Orthoclase feldspar Feldspar scratches a knife blade or window glass.

7.
 Quartz  

8.
 Topaze  

9.
 Corundum  

10.
 Diamond Diamond is the hardest known mineral and scratches all known materials.