Peridot

It is an igneous rock and is found  in North Carolina, Arizona, and Hawaii within the United States. The chemical composition of peridot is (Mg, Fe)₂SiO₄,  meaning that it is mafic. It has white streaks and is green. It is in the olivine group as evidenced by it's green color. It is the birthstone of August. Peridot ranges in color from light yellow-green to a bright lime green. If it has hues of yellow or brown it is no longer as valuable. It is a semiprecious stone.

It is shown in this picture with basalt.

Rocks

Peridot/Olivine: This is in my birthstone./ It is also a silicate

Pyrite: Fools Gold. I remember getting really angry when I was younger because I thought I was rich. It is sulfide and has an isometric dipole.

Amethyst: It is said to protect it's owner from drunkness/intoxication. It is silicate SiO2.

Saint Cecilia Granite: The most common type of granite that has hornblend, feldspar, and quartz. It is the most common granite used in kitchen countertops.

Biotite: This rock is formed of silicate material. Even though it isn't used commercially very much. It is used in decorative concrete. When I worked for a construction company they used this as a sub for true marble. It is mica.