Definition

Noun: A category of rock-forming, inosilicate minerals characterized by a shared double-chain silicate crystal structure. These minerals typically contain complex combinations of elements, primarily sodium, calcium, magnesium, iron, and aluminum.

Usage

The term is used in geology and mineralogy to classify a major group of silicate minerals. It refers to the collective set, not an individual mineral. - The amphibole group is one of the most common mineral groups in metamorphic and igneous rocks. - Hornblende and actinolite are both members of the amphibole group.

Advanced Usage

• "Amphibole-group minerals": A more explicit phrase referring to the individual minerals within this category.
  • The presence of amphibole-group minerals like glaucophane indicates high-pressure metamorphism.

Variants and Related Words

• Amphibole (noun): The general name for any mineral belonging to the amphibole group.
  • Amphibole crystals are often elongated and dark-colored.
• Amphibolite (noun): A metamorphic rock composed primarily of amphibole-group minerals and plagioclase feldspar.

Synonyms

• Inosilicates (double-chain): A more technical, structural classification term.
• Hornblende group: An older, less precise term sometimes used synonymously, though hornblende is a specific series within the amphibole group.

Related Phrases

• Amphibole asbestos: Refers to the fibrous varieties of minerals from the amphibole group, such as tremolite or actinolite, which are regulated health hazards.
  • Chrysotile (serpentine asbestos) is structurally different from amphibole asbestos.

Noun

1. a group of minerals with similar crystal structures containing a silicate chain and combinations of chiefly sodium and calcium and magnesium and iron and aluminum