feldspar
C2Technical / Scientific
Definition
Meaning
A group of abundant rock-forming minerals, typically light-coloured, composed of aluminium silicates combined with potassium, sodium, calcium, or barium.
The most common mineral group in the Earth's crust, a key component of igneous, metamorphic, and some sedimentary rocks, and a primary source of the alkali metals used in ceramics and glassmaking.
Linguistics
Semantic Notes
The term is a group name for several related minerals (e.g., orthoclase, plagioclase). It is almost always used as a mass noun (uncountable) in geological contexts, though countable forms ('feldspars') refer to the different types within the group.
Dialectal Variation
British vs American Usage
Differences
No significant difference in meaning or usage. The spelling 'feldspar' is standard in both, though the older German-derived spelling 'felspar' is occasionally seen in older British texts.
Connotations
None; purely technical term.
Frequency
Equally low-frequency in general language but standard in geology/mineralogy in both regions.
Vocabulary
Collocations
Grammar
Valency Patterns
The granite contains [QUANTIFIER] feldspar.[TYPE] feldspar is a major component of [ROCK TYPE].Feldspar weathers to form [MINERAL/CLAY].Vocabulary
Synonyms
Strong
Weak
Usage
Context Usage
Business
Used in industries like ceramics, glass, and fillers: 'The supplier guarantees the purity of the potash feldspar for our glaze batch.'
Academic
Core term in geology, earth sciences, and materials science: 'The thin section revealed perthitic exsolution textures within the feldspar.'
Everyday
Rare. Might occur in hobbyist contexts (rock collecting, jewellery): 'This granite pebble has shiny bits of feldspar in it.'
Technical
Precise mineralogical description: 'The sample's XRD pattern confirmed the presence of microcline feldspar and quartz.'
Examples
By Part of Speech
verb
British English
- N/A
American English
- N/A
adverb
British English
- N/A
American English
- N/A
adjective
British English
- The feldspar-rich granite was quarried locally.
- A feldspar-bearing pegmatite vein was discovered.
American English
- The feldspar-rich granite was quarried locally.
- A feldspar-bearing pegmatite dike was identified.
Examples
By CEFR Level
- Granite often contains grey or pink feldspar.
- The shiny mineral in this stone is feldspar.
- Feldspar is a major component of the Earth's crust and is common in igneous rocks like granite.
- As feldspar weathers, it breaks down into clay minerals.
- Petrographic analysis distinguished between the potassium feldspar and the more calcium-rich plagioclase in the sample.
- The geochemical signature indicated the feldspar had undergone significant sericitisation.
Learning
Memory Aids
Mnemonic
Think of a FIELD of SPARkling crystals. 'Feld' is German for 'field', and 'spar' is an old mining term for a crystalline mineral.
Conceptual Metaphor
Often conceptualised as a BUILDING BLOCK or SKELETON of the continental crust.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- The Russian term 'полевой шпат' is a direct calque and is correct.
- Avoid translating it as 'spar' alone, as 'spar' in English can refer to other shiny minerals or a ship's mast.
Common Mistakes
- Misspelling as 'feltspar' or 'feldsparr'.
- Using it as a regular countable noun incorrectly (e.g., 'three feldspars' instead of 'three types of feldspar' or 'three feldspar crystals').
Practice
Quiz
What is the primary industrial use of feldspar?
FAQ
Frequently Asked Questions
No, it is a group name for several closely related aluminosilicate minerals, including orthoclase, microcline, and plagioclase series minerals.
It is pronounced FELD-spar. The 'd' can be very subtle or silent. In American English, the final 'r' is pronounced.
Both are silicate minerals, but quartz is pure silicon dioxide (SiO2) and is harder. Feldspar contains aluminium and other elements (K, Na, Ca) and has cleavage planes, whereas quartz does not.
Yes. The white, glossy part of porcelain (like a bathroom sink) and the glaze on ceramic dishes contain feldspar. It is also a key ingredient in glass.