What does feldspathic mean?
Feldspathic is an adjective meaning containing, consisting of, or relating to feldspar, the family of light-colored aluminosilicate minerals that constitute the most abundant group in the Earth's crust. In geology, the term describes rocks such as feldspathic sandstone or feldspathic basalt, indicating a notable proportion of feldspar in their makeup. In ceramics, it is equally at home: feldspathic glazes, built on feldspar as a primary flux, produce the smooth, glassy surfaces prized in both ancient Chinese porcelain and modern stoneware. The word is technical and neutral in tone, encountered mainly in scientific writing, trade literature, and craft discussion rather than casual conversation. Its value lies in precision — where 'mineral-rich' is vague, 'feldspathic' tells a geologist or potter exactly what to expect.
adjectiveOf, relating to, consisting of, or containing feldspar, a group of abundant rock-forming aluminum silicate minerals.
- Containing or consisting of feldspar (of rocks, sands, and minerals).
- Relating to or made with feldspar, especially of ceramic glazes and porcelains rich in feldspar.
"The feldspathic glaze gave the stoneware its characteristic milky, softly mottled surface."
"The granite's feldspathic composition gave it a distinctive pinkish hue."
"Chinese potters of the Song dynasty perfected feldspathic glazes that remain prized today."
Feldspar makes up roughly 60% of the Earth's crust — so calling a rock 'feldspathic' is often just describing the ground beneath your feet.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of feldspathic
Feldspathic derives from feldspar, a term borrowed in the 18th century from German Feldspat, literally 'field spar' — Feld meaning field and Spat meaning a non-metallic mineral or spar. The adjective was formed with the Latinate suffix -ic. It shares its root with related mineralogical terms such as feldspathoid (a mineral resembling feldspar) and, more distantly, with spathic, from the same German word for spar.
How feldspathic is actually used
A technical term used chiefly in geology, mineralogy, and ceramics rather than in everyday speech. It carries no connotation beyond its descriptive, scientific function.
Easily confused with feldspathic
Spathic means relating to spar (especially calcite) in general, while feldspathic refers specifically to feldspar.