Definition of "dichroism" [di•chro•ism]

• Chemistry The property possessed by some solutions of showing different colors at different concentrations. (noun)
• Chemistry The property possessed by some crystals of exhibiting two different colors when viewed along different axes. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "He also studied the orientation of purines and pyrimidines in tobacco mosaic virus and in nucleic acids, by measuring the ultraviolet dichroism of oriented specimens, and he studied, with the visible-light polarizing microscope, the arrangement of virus particles in crystals of TMV and measured dry mass in cells with interference microscopes."
• "And as in some real rubies there are found slight hollows corresponding or analogous to the bubbles found in melted glass, it becomes a matter of great difficulty to distinguish the real from the imitation by such tests as hardness, specific gravity, dichroism, and the like, so that in such a case, short of risking the ruin of the stone, ordinary persons are unable to apply any convincing tests."
• "This stone is doubly refracting, exhibiting extremely strong dichroism, especially in the blue and the green varieties."