Definition

Adjective 1. Of or relating to plagioclase: Describes anything pertaining to, characteristic of, or composed of the mineral plagioclase feldspar.

Usage

The adjective "plagioclastic" is a technical term used primarily in geology and mineralogy. It is used to describe rocks, textures, or features that are associated with or dominated by the mineral plagioclase.

Examples

• The thin section revealed a plagioclastic texture, indicating the rock's origin.
• This plagioclastic basalt is common in the region's volcanic flows.
• Analysis confirmed the plagioclastic nature of the feldspar crystals.

Advanced Usage

• Plagioclastic fabric: A term describing the specific arrangement or orientation of plagioclase crystals within a rock.
• Plagioclastic groundmass: Refers to the fine-grained matrix of a rock that is chiefly composed of plagioclase.

Variants and Related Words

• Plagioclase (n): The specific series of feldspar minerals (such as albite, anorthite) to which the adjective refers.
• Feldspathic (adj): Relating to or containing feldspar, a broader category that includes plagioclase.

Synonyms

• Feldspathic (when the context specifies the feldspar is plagioclase)
• Plagioclase-bearing

Notes

"Plagioclastic" is a highly specialized term. In most general or non-scientific contexts, the more common noun "plagioclase" is used instead (e.g., "a plagioclase crystal," not "a plagioclastic crystal"). The adjective form is typically reserved for describing the overall character or composition of a rock.

Adjective

1. of or relating to plagioclase