From German Feldspat 'field spar,' named for the common mineral found in fields or for its flat cleavage planes.
A group of rock-forming minerals making up about 60% of the Earth's crust, found in most igneous and metamorphic rocks.
From German Feldspat (later Feldspath), from Feld 'field' + Spat 'spar, non-metalite mineral.' Named by Swedish mineralogist Daniel Tilas in 1740, possibly because pieces of feldspar were found in fields among agricultural land, or because it cleaved in flat 'field-like' planes. Key roots: *pelh₂- (Proto-Indo-European: "flat, broad (whence field)").