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Lamellar twining In labradorite

This is a picture of a stone called Laborite in the sun. Labradorite is made up of feldspar and when the feldspar is closely spaced it causes lamellar twining. When Light hits the crystals surface it encounters stacked layers of different composition. The layers spilt and reflect the light in different angles. As a result colors interfere and it creates the shimmering colorful effect called labradorescence. The colors that are displayed depend on the thickness and arrangement of the layers within the crystal.