Hardness is the resistance of a gem to scratching and abrasion. It is one of the key qualities of a gemstone.
Diamond is the hardest gemstone.
The second hardest gemstone is corundum (ruby and sapphire).
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. They 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. ...
Asked in Jewelry
What is the difference of pearl gemstone to a diamond gemstone?
Pearl is made by a living organism (an oyster) and is soft. Diamond is made deep in the earth and is the hardest substance known to man. ...
Asked in Earth Sciences
Which is the second natural hardest substance in the world?
The second hardest substance in the world is mineral lonsdaleite, or hexagonal diamond. It's made up from the same materials as diamonds, but it has a slightly different structor. Mineral lonsdaleite is extremely rare in nature. ...