What does feldspathose mean?
Feldspathose is a technical adjective used chiefly in geology to describe rocks, minerals, or sediments that contain, consist of, or resemble feldspar — the most abundant group of minerals in Earth's crust. A feldspathose sandstone, for example, is one noticeably rich in feldspar grains alongside its quartz content, while feldspathose granite owes much of its pale pink or white coloring to feldspar crystals. The word functions identically to the far more common 'feldspathic,' and indeed has been largely displaced by it in modern scientific writing; today it appears mainly in older geological literature or as a deliberate stylistic variant. Because it belongs to specialist vocabulary, it carries a formal, scholarly register rather than everyday usage. Its ultimate root lies in the German word 'Feldspar' (from Feld, field, and Spath, spar), which entered English scientific terminology in the eighteenth century.
adjectiveRelating to, consisting of, or containing feldspar; having the character or composition of feldspar.
- Relating to or consisting largely of feldspar; having a composition or appearance like that of feldspar.
"The granite's pale pink hue comes from its abundance of feldspathose minerals."
"The cliff face was composed of coarse feldspathose granite that glittered in the afternoon sun."
"Sedimentologists identified the deposit as feldspathose sandstone, rich in weathered potassium feldspar grains."
Before 'feldspathic' won the naming war, geologists had a whole menu of options — feldspathose, feldspathic, even feldspathoid — all built on a German word meaning 'field spar.'
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of feldspathose
The word derives from feldspar itself, a term borrowed from German 'Feldspat' (literally 'field spar'), so named because early miners found spar-like crystals scattered in tilled fields. The suffix '-ose' was added to form an adjective meaning 'of the nature of feldspar,' parallel to other '-ose' adjectives in technical English. Related derivatives include 'feldspathic' and 'feldspathoid', which share the same root. The compound entered English geological vocabulary in the eighteenth century as mineralogy developed its systematic descriptive language.
Related word forms
How feldspathose is actually used
A technical term of petrology and mineralogy; rare and somewhat dated, with 'feldspathic' being strongly preferred in contemporary scientific literature. Encountered mainly in older geological texts.
Easily confused with feldspathose
Both mean the same thing — containing or resembling feldspar — but 'feldspathic' is by far the more common form in modern geological writing, while 'feldspathose' is a rarer, largely older variant.