Definition

1. Noun:
   • A blue mineral: Cordierite is a silicate mineral composed of magnesium, iron, aluminum, silicon, and oxygen. It is known for its distinctive blue to violet-blue color and is often used as a gemstone.

Usage Examples

• Noun:
  • The geologist identified the blue crystal in the sample as cordierite.
  • Cordierite is sometimes cut and polished for use in jewelry.

Advanced Usage

• "Pleochroic cordierite": Refers to the optical property of cordierite where it can show different colors (e.g., yellow, blue, violet) when viewed from different angles.
  • The pleochroic nature of the cordierite made it a fascinating specimen under the microscope.

Variants and Related Words

• Iolite (n): A common gemological name for transparent, gem-quality cordierite.
  • The jeweler offered a beautiful ring featuring a deep blue iolite.

Synonyms

• Iolite: (Gemology) A synonym for gem-quality cordierite.
• Dichroite: An older, less common name for cordierite, referencing its strong pleochroism.

Notes on Meaning

• The primary meaning of "cordierite" is as a specific mineral species. Its value and recognition stem from its use in geology/mineralogy and, when of gem quality, in jewelry. It is not typically used in idiomatic or phrasal verb constructions.

Noun

1. a blue mineral of magnesium and iron and aluminum and silicon and oxygen; often used as a gemstone