Diamond – $6 Million/Kg

These gems have made it to almost every lady’s dream jewelry because who wouldn’t want an exorbitant shiny diamond engagement ring? First discovered in South Africa, Diamond is the hardest natural substance on earth. They are the most glamorized and profoundly marketed gemstones in the world. Unlike rubies, it is easy to come by a sheer quality diamond, as long as you have the money for it.

Red diamonds are however an exception as they are the rarest stones on the planet. There are less than 30 known red diamonds to humans and one can go for up to $5,000,000,000!