Definition

Noun: A green to grayish-green mineral belonging to the amphibole group. It is a silicate mineral containing calcium, magnesium, and iron, and is often found in fibrous or columnar crystal forms.

Usage

"Actinolite" is used specifically in the fields of geology, mineralogy, and related sciences to identify and describe this particular mineral. It is a technical term.

Examples

• Noun:
  • The geologist identified the green fibrous crystals in the rock sample as actinolite.
  • Actinolite is commonly found in metamorphic rocks such as schist and greenschist.
  • Under the microscope, the actinolite needles displayed characteristic pleochroism.

Advanced Usage

• "Actinolite asbestos": A specific, fibrous variety of actinolite that is regulated as a form of asbestos due to its health hazards.
  • Older building materials sometimes contained dangerous actinolite asbestos.

Variants and Related Words

• Actinolitic (adj): Having the characteristics of or containing actinolite.
  • The rock had an actinolitic texture.

Synonyms

• Amphibole mineral: (broader category) Actinolite is a specific member of the amphibole group of minerals.

Notes on Meaning

This word has a single, precise scientific meaning. It does not have idiomatic uses or phrasal verbs.

Noun

1. a green mineral of the amphibole group; calcium magnesium iron silicate