spinel

/spi'nel/

Thân thiện

A jeweler examines a red spinel under a bright light.

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.

Học thuật

Noun

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