1) Optical phenomenon 
displaying different colours when seen from different directions
• (a.) Having the property of pleochroism.
An effect where the properties of diffraction in a stone cause it to look a different colour depending on the angle you observe it from. Many stones are dichroic or trichroic.
Synonym: pleochromatic. ... Origin: pleo-+ G. Chroa, colour ... (05 Mar 2000) ... 
Ple`o·chro'ic adjective Having the property of pleochroism. 
Type: Term Pronunciation: plē′ō-krō′ik Synonyms: pleochromatic
The luminous property that some minerals and gemostones have, whereby they appear to have more than two colours particularly when viewed from different angles
[adj] - of or relating to or having pleochroism
pleochroic, pleochromatic, pleochroous 1. Showing different colors when viewed from different directions. 2. A reference to a crystal showing different colors when viewed by light polarized in different directions.
adjective of or relating to or having pleochroism