What are the top ten hardest stones in the world?

Answer 1

I am not an expert, but I was interested to know this answer myself, a while ago. My research led me to this:

Stones harder than Steel

1. Diamond - the hardest mineral on earth;

2. Corundum* (depending on color: Ruby, Padparadscha, sapphire);

2. Diorite* (not a precious stone, therefore rarely mentioned);

3. Chrysoberyl (depending on color: Alexandrite, Cat's Eye or Cymophane);

4. Granite (not a precious stone, therefore rarely mentioned);

5. Topaz;

6. Quartz;

7. Feldspar;

All the above stones are stronger than steel.

8. Apatite (can be scratched by steel);

9. Fluorite (can be scratched by steel);

10. Calcite (can be scratched by a coin);

The following two can be scratched by fingernail:

11. Gypsum;

12. Talc;

*I'm still trying to find out if Corundum is harder than Diorite, or vice-versa.