How do I determine the the hardness of marble?

All minerals have a certain hardness. The hardness of a mineral is determined by performing a scratch test. A scratch test is based on the Moh’s scale of hardness. A German scientist invented this scale by taking several known, pure minerals and seeing which mineral scratched each other. If one mineral was scratched by another the scratched mineral was softer than the mineral that did the scratching. The table below shows this scale. One is the softest mineral and ten is the hardest
MOHS SCALE OF RELATIVE HARDNESS
1. Talc
2. Gypsum
3. Calcite
4. Fluorite
5. Apatite
6. Orthoclase
7. Quartz
8. Topaz
9. Corundum
10. Diamond
(You can purchase these minerals at most rock collecting stores.)