Peridot

Peridot (pronounced Pear-Eh-Doe) is a variety of the mineral Olivine and is one of very few gems that only comes in one color which is like a Tinkerbell green. Unlike most gems it gets its color from its own crystal structure instead of a mineral impurity. Peridot is also one of the oldest gems on the planet existing for around 3.8 billion years! And like diamond its also found in the mantel of earth where as most just are found within the crust. Very underrated and interesting gem to say the least

Hardness: 6.5 – 7
Composition: (Mg,Fe)₂SiO₄