Labradorite

Labradorite is a plagioclase feldspar, which feldspar is the most common mineral in the crust of the earth. 

Labradorite is wildly colorful for the same optical reasons that oil flashes back rainbows at you when it floats in water. Different layers of crystals cause the light to reflect back with different colors. 

Labradorite can be found throughout the world including in the United States but the major commercial deposits are in Canada, Madagascar and Finland. 

Labradorite is a very popular stone to give as a gift as the rainbows inside are sure to please even the grumpiest of grumps. 

The natives of the northlands believed that the northern lights went "home" into the labradorite rocks during the day while they were not dancing in the sky. 

Labradorite is a 6.5 on the Moh's scale of hardness and has a distinct crystal cleavage. Labradorite is good for daily wear jewelry as long as you are mindful to not knock it around too much.