Definition

1. Noun:
   • A hard, glassy mineral: A naturally occurring inorganic solid with a crystalline structure, characterized by its hardness and vitreous (glassy) luster.
   • Composition: It consists primarily of an oxide of magnesium and aluminum (MgAl₂O₄), though other metal ions can substitute, leading to color variations.
   • Occurrence and Use: Found in various geological environments; its different colors, such as red, blue, violet, or black, make it valuable as a gemstone.

Usage Examples

• Noun:
  • The jeweler showed us a beautiful red spinel set in a ring.
  • Spinel is often found in the same mines as rubies and sapphires.
  • This specimen is a classic example of the mineral spinel.

Advanced Usage

• "Spinel group": Refers to a broader class of minerals with the same crystal structure as spinel, which can include other compositions like chromite (FeCr₂O₄) or magnetite (Fe₃O₄).
  • Many important magnetic materials belong to the spinel group.

Variants and Related Words

• Spinel-like (adj): Having characteristics similar to spinel.
  • The synthetic crystal had a spinel-like structure.

Synonyms

• Mineral: (a broader category) A solid, naturally occurring inorganic substance.
• Gemstone: A mineral, rock, or organic material used for adornment. (Note: Not all spinel is gem-quality, and not all gemstones are spinel.)

Different Meanings

• The word "spinel" is specific and does not have other common, unrelated meanings in general English. Its primary and almost exclusive use is in mineralogy and gemology.

Noun

1. a hard glassy mineral consisting of an oxide of magnesium and aluminum; occurs in various colors that are used as gemstones