what is the hardest stone known to man
What stone is the second hardest stone? In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. The â¦ y are the hardest stone. The ruby is the second-hardest precious stone. A ruby is a pink to blood-red gemstone, a variety of the mineral corundum. What is the second hardest stone in nature?