noun. a hard glassy mineral consisting of an oxide of magnesium and aluminum; occurs in various colors that are used as gemstones.
- ruby spinel
- atomic number 12
- spinel ruby
Sentences with spinel
1. Noun, singular or mass
A pure spinel is white, but is most often seen in many different colors, such as red, pink and black.
2. Noun, plural
Many other gemstones like garnets, peridots, tourmalines, iolites, spinel and zircons fall between 6 and 7.5 on the hardness scale.