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

Granite is a natural stone composed primarily of silicates, such as quartz, feldspar, and mica. —Caitlin Sole, Better Homes & Gardens, 28 Nov. 2025

The handmade glass is made from a mixture of sand, limestone, feldspar and other materials. —Christine Tannous, IndyStar, 13 Nov. 2025

Tiny quartz and feldspar crystals, no bigger than a human hair, that carried microscopic planar deformation features. —Rupendra Brahambhatt, Interesting Engineering, 21 Sep. 2025

The desert sand at the test site is composed mostly of grains of quartz and feldspar, with small crystals of calcite, hornblende, and augite mixed in. —David Bressan, Forbes.com, 16 July 2025

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

Rhymes for feldspar

• adar
• afar
• ajar
• alar
• ansar
• bazaar
• bizarre
• boxcar
• boyar
• bulbar
• cachar
• cigar

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