Ruby and Sapphire are the two main varieties of what gemstone?
Answer Corundum
Corundum is among the hardest types of gemstones in the world, ranking 9 on the Mohs Scale. Its two main varieties are ruby and sapphire, which are some of the most famous gemstones known to man. Rubies are red due to the presence of chromium, and sapphires, though usually blue, can exhibit a range of colors depending on what transition metal is present.
Asked by Ben Jenkins · Last updated 2 years ago · 14.5K views
