Any of the group of feldspars rich in sodium and/or potassium.
More example sentences
- Olson states that the first mineral to be deposited was a reddish alkali feldspar, followed by abundant deposition of epidote and smaller amounts of pumpellyite.
- Of these, alkali feldspar, particularly orthoclase, is the most common.
- The first phase of diagenetic albite constitutes an impure, turbid variety including albitized grains of original plagioclase and alkali feldspar.
Definition of alkali feldspar in:
- The British & World English dictionary