Labradorite with Schiller effect

3D Model

Size: 7 x 6 x 3 cm

Formula: (Ca,Na)(Al(Al,Si)Si2O8)

Description: Labradorite (var. of Anorthite) is a plagioclase feldspar with an albite:anorthite molar ratio ranging from 30:70 to 50:50. Labradorite can display an iridescent optical effect (or schiller) known as labradorescence, which is a strong play of iridescent blue, green, red, orange, and yellow colors.

The color display is from lamellar intergrowths inside the crystal. The resulting color effect is caused by a ray of light entering a layer and being refracted back and forth by deeper layers. This refracted ray is slowed by the extra travel through the layers and mixes with other rays to produce a light ray coming out that has a different wavelength than when it went in. The effect depends on the thickness and orientation of the layers.

Website: http://geology.uaic.ro/muzee/mineralogie/

Concept & 3D-modelling by Andrei Ionut APOPEI