ruby spinel
Noun A type of spinel mineral valued as a gemstone, typically characterized by a dark red color. It is a specific variety of spinel that resembles ruby in color but is a distinct mineral species.
"Ruby spinel" is used as a countable noun to refer to individual gemstones of this type. It names a specific gem material. - The antique ring was set with a large ruby spinel. - She prefers the color of ruby spinel to that of many rubies.
The term is primarily used in gemology, jewelry, and mineralogy to distinguish this red spinel from true ruby (corundum) and other colored spinels. - In historical jewelry, many stones thought to be rubies were later identified as ruby spinels.
- Spinel (n): The broader mineral group to which ruby spinel belongs. Spinel occurs in many colors.
- Balas ruby (n): An archaic, historical name for a pale red variety of spinel.
- Red spinel: A more descriptive, less formal synonym.
- Spinel ruby: An alternative term with the same meaning.
It is crucial to distinguish "ruby spinel" from "ruby." While visually similar, they are chemically and structurally different minerals. "Ruby" is red corundum (aluminum oxide), while "ruby spinel" is a magnesium aluminum oxide. The term itself specifies that it is a spinel that looks like a ruby.
- a spinel used as a gemstone (usually dark red)