Opalescences

Part of speech: noun

Definitions

1. A phenomenon characterized by the play of colors similar to those seen in opals, often exhibiting shifting hues in reflected light
2. The visual effect displayed by certain materials, resulting in a spectrum of colors that shift and changes under different lighting conditions
3. An optical quality observed in substances that appear to show iridescent colors, reminiscent of the inner reflections seen in opal gemstones

Etymology: The plural "opalescences" simply means several instances or kinds of the shimmering, milky play of colour that the stone opal is known for. It is the plural of "opalescence," which is formed from "opal" plus the suffix "-escence," meaning "becoming or showing a quality." That suffix comes from Latin "-escere," an inceptive ending that marks the beginning of a state, and English took it up in forms such as "iridescence." The base word "opal" has a longer trail. It passed from Sanskrit "upala," meaning "stone," through Medieval Greek "opállios," and then into Latin as "opalus," from which French "opale" and English "opal" descended. The stone's name thus carries the simple idea of "stone" at its core, while the English coinage "opalescence" describes the stone's characteristic glow.