Definition of pleochroism in US English:

pleochroism

noun

  • See pleochroic

    • ‘Biotite shows the same pleochroism as in the granodiorite.’
    • ‘These produced iolite gems with excellent transparency and pleochroism; they weighed 0.5, 1.0, and 1.49 carats.’
    • ‘Optically, purple apatite commonly shows slight bluish to reddish pleochroism.’
    • ‘Cordierite is often referred to as dichorite because of its strong pleochroism, which produces gemstones that appear to change shades of color, depending on the viewing angle.’
    • ‘Biotite occurs as interstitial grains with strong pleochroism from light yellowish-green to dark brown.’

Pronunciation

pleochroism

/-ˈkrōˌizəm/