What is the trade term for a type of labradorite?

The trade term for a type of labradorite is "rainbow moonstone." This designation reflects the stone's optical characteristics, specifically its adularescence, which results in a phenomenon where light seems to glow from within the stone, creating a play of colors. Although labradorite and rainbow moonstone are both feldspathic minerals, rainbow moonstone specifically refers to a variety of labradorite that exhibits this distinct shimmering effect, often displaying a soft blue to white sheen on a transparent base.

The choice of "rainbow moonstone" is widely accepted in the gem trade for marketing and identification purposes, helping consumers recognize the unique visual qualities of the stone. It's important to note that while other options like sunstone and spectrolite may also involve unique optical properties and colors, they are distinct types of feldspar minerals, and opal, while renowned for its play-of-color, belongs to an entirely different mineral category and does not share the same structural properties as labradorite.