feldspar

noun

feld·​spar ˈfel(d)-ˌspär 

: any of a group of crystalline minerals that consist of aluminum silicates with either potassium, sodium, calcium, or barium and that are an essential constituent of nearly all crystalline rocks

Examples of feldspar in a Sentence

Recent Examples on the Web

Made of clay and feldspar and covered in glaze, this earthenware pottery is celebrated for its timelessness and durability. —Betsy Cribb Watson, Southern Living, 4 Oct. 2024

The town’s pegmatites are composed of about 65 percent feldspar, 25 percent quartz, 8 percent mica and trace amounts of other minerals. —Olatunji Osho-Williams, Smithsonian Magazine, 3 Oct. 2024

Now cooled and worn, the rocks around Spruce Pine has the look of a dirty snowball thanks to a combination of feldspar, mica, and quartz. —Adam Clark Estes, Vox, 7 Dec. 2018

Consisting primarily of feldspar and quartz, aplite is formed at a late stage of the magma crystallization. —Roger Naylor, The Arizona Republic, 5 Sep. 2024

Word History

Etymology

modification of obsolete German Feldspath (now Feldspat), from German Feld field + obsolete German Spath (now Spat) spar

First Known Use

1772, in the meaning defined above

Kids Definition

feldspar

noun

feld·​spar ˈfel(d)-ˌspär 

: any of a group of crystalline minerals that consist of silicates of aluminum with potassium, sodium, calcium, or barium and that are a basic part of nearly all crystalline rocks