feldsparrike

Feld sparike is a term encountered in some geological texts and in Norwegian-language sources to describe a rock body or region characterized by a feldspar-rich mineral assemblage. It is not a formal category in international geology, and its precise meaning can vary by author. Broadly, it refers to rocks in which feldspar is the dominant mineral, typically comprising a majority of the mineral weight, often more than half the rock.

Feldspar minerals include orthoclase (potassium feldspar), microcline, and plagioclase varieties (albite to anorthite). In feldsparrike rocks, these minerals contrast with smaller amounts of quartz, mica, amphibole, and other phases. Textures range from coarse-grained granites and granodiorites (phaneritic, crystalline) to pegmatites with very large crystals. Weathering of feldspar-rich rocks commonly yields clay minerals and contributes to feldspar-rich soils.

Geologically, feldsparrike rocks are typical of felsic igneous suites formed by differentiation of silica-rich magmas, as well as certain metamorphic and sedimentary settings where feldspar is preserved. They are economically significant because feldspar is a major industrial mineral, used in ceramics, glassmaking, and fillers.

Because feldsparrike is not a standardized term, its use should be clarified in context, particularly the criteria for "feldspar-rich" and the targeted rock or terrain.