1. It is the hardest natural substance found on earth.
2. It forms from metamorphosed carbonate rock.
3. It is the most common rock on earth.
4. In 5000 BC, Mesopatamians used this rock to make beads.
5. It has been used for hammers, axes and fish hooks.
6. The biggest nugget was found in Australia in 1869 weighing 169 pounds. What was it?
7. Mirrors are coated with this rock because it reflects light.
8. This gemstone is stronger than all others except diamonds.
9. Its reddish hue comes from traces of the mineral chromium.
10. It is the birthstone for May and may be given on the 20th or 35th wedding anniversary.
Image courtesy www.westcoasstdiamond.ca.