feld·​spar ˈfel(d)-ˌspär How to pronounce feldspar (audio)
: 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

Example Sentences

Recent Examples on the Web Granite is a siliceous stone composed primarily of silicates, such as quartz, feldspar, and mica. Caitlin Sole, Better Homes & Gardens, 4 Aug. 2022 Bauxite is a complex mix of the minerals gibbsite, boehmite, and diaspore, formed as less stable minerals like feldspar and mica react with water. David Bressan, Forbes, 4 July 2021 The exact composition of porcelain varies depending on its use and the manufacturer, although one common ingredient is kaolin, a soft white clay that is combined with other ingredients like bone ash, sand, magnesium, quartz, and feldspar. Melissa Locker, Southern Living, 30 June 2021 The most common lava rock found at Mount St. Helens is indeed Dacite, composed predominantly of plagioclase feldspar and quartz (pure silicon-dioxide). David Bressan, Forbes, 18 May 2021 The sand reflects the rocky outcrops found inland and along the coast and is composed mostly of grains of quartz, feldspar, limestone and fragmented shells. David Bressan, Forbes, 27 Apr. 2021 Basalt is the most common rock on Earth, formed directly by crystallization of feldspar, pyroxen, olivine and quartz from a magma rich in iron and silica. David Bressan, Forbes, 10 Mar. 2021 Generations of Spruce Pine miners tossed the quartz aside in favor of the feldspar and mica. Sam Farmer, Los Angeles Times, 11 Nov. 2020 Later the region was mined for the feldspar in the granite ledges. courant.com, 12 Aug. 2019 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'feldspar.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


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

Time Traveler
The first known use of feldspar was in 1772

Dictionary Entries Near feldspar

Cite this Entry

“Feldspar.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/feldspar. Accessed 4 Dec. 2022.

Kids Definition



feld·​spar ˈfel(d)-ˌspär How to pronounce feldspar (audio)
: 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

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