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Marble is a relatively soft
stone. On a measurement of hardness (MOHS),
marble is approximately a three out of ten.
Marble is made of calcium, just like your teeth.
If you eat something to hard you will break your
tooth. If you eat a lot of sugar you will get a
cavity. Stone reacts the same way. If an
improper chemical is applied to the surface,
corrosion will begin to form cavities in the
stone.
Listed below is the famous Measurement of
Hardness (MOH) Scale for stone. This is a guide
developed in the 1800's which helps evaluate the
strengths and weaknesses of the stone being
used. For example, softer stones would require
the use of a less active chemical and a more
frequent dust mopping program.
Measurement of Hardness Scale
1. Talc
2. Gypsum
3. Calcite (Most Marbles)
4. Fluorite
5. Apatite
6. Feldspar (Granite)
7. Quartz (Granite)
8. Topaz
9. Corundum
10. Diamond
The objective of the MOH Scale is to measure
stones resistance to hardness. When sediment and
grit are harder than the surface, they will
scratch and harm the stone. For example, a piece
of hard plastic is about a 2.0. It will not
scratch #3 Calcite (Marble). However, a piece of
sand that measures a 6, will scratch #3 Calcite
but will not scratch #7 Quartz which is Granite.
The harder the stone, the more resistant it is
to abrasion. Exterior sediment that is tracked
in to buildings approximately measures from 3.0 to 7.0.
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