Main Entry: feld·spar

Pronunciation: \ˈfel(d)-ˌspär\

Function: noun

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

Date: 1772

: 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