HARDNESS

Marble is a soft stone - grade 3 MOH. The MOH scale is one that measures the relative hardness of materials, from grade 1 to 10. Marble has predominantly calcite in its composition, what means that any other harder material may scratch it. It has little abrasion resistance and is vulnerable to chemical products. On the other hand, granite is composed mainly of feldspar and quartz and has a 6 to 7 MOH hardness, conferring excellent resistance properties to traffic, abrasion and to the action of chemical products. That way granite became a favorite for kitchen counter tops, external covering of buildings, high traffic flooring, etc.

Knowing these facts about stones might help when choosing the appropriate material for each kind of job.

Examples of materials in the MOH scale:

  1. TALC
  2. GYPSUM
  3. CALCITE (almost any marble)
  4. FLUORITE
  5. APATITE
  6. FELDSPAR
  7. QUARTZ
  8. TOPAZ
  9. CORUNDUM
  10. DIAMOND

Regarding what was illustrated before, materials with higher hardness may scratch the ones less hard, for that reason diamonds have many industrial applications as a cutting material.

A grain of sand usually has a hardness of 6 MOH and might scratch marble, but not granite, which is as hard as or even harder than sand. Outside sediments that are generally brought inside houses and buildings correspond to 3 to 7 MOH.