What does calcspar mean?
Calcspar is the traditional miner's and mineralogist's name for calcite, the common crystalline form of calcium carbonate (CaCO3). It typically appears as white, colourless, or pale-tinted masses lining veins and cavities in limestone and ore deposits, and it famously occurs as large, optically clear crystals known as Iceland spar, which exhibit double refraction — splitting light passing through them into two beams. The name combines 'calc', from Latin calx meaning lime, with 'spar', an old Germanic mining word for a non-metallic, readily cleaved crystalline mineral. Though once routine in the vocabulary of miners and geologists, calcspar has largely given way to 'calcite' in modern scientific writing, surviving mainly in older literature, field guides, and collectors' terminology. It remains useful shorthand when describing the glassy carbonate gangue that so often accompanies metal ores.
nounA miner's term for the mineral calcite, crystalline calcium carbonate, occurring in transparent or variously tinted masses and crystals.
- The mineral calcite (calcium carbonate), especially as found in veins, cavities, or crystal forms in ore deposits.
"The vein was lined with milky-white calcspar that glittered under the miner's lamp."
"Chunks of amber-tinted calcspar had formed along the walls of the limestone cave."
"Nineteenth-century geologists catalogued every specimen of calcspar brought back from the Cornish mines."
As a mass-mineral term it is normally uncountable ('calcspar'); a plural is occasionally written for distinct specimens or varieties.
"The museum's drawers held calcspar specimens from a dozen different mines."
Transparent calcspar from Iceland — Iceland spar — split light into two rays, and one damaged crystal of it may have let Vikings navigate by the sun.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of calcspar
Calcspar derives from Latin calx, 'lime' or 'limestone', combined with 'spar', a mining term of Germanic origin (German Spat) denoting a crystalline, easily cleaved non-metallic mineral. The compound arose in the mining and early scientific literature of the seventeenth to eighteenth centuries, when European miners applied 'spar' broadly to such minerals. Its relatives include calcium, calcareous, calcite, and calcify, all tracing back to the same Latin root.
How calcspar is actually used
An older, largely technical or historical term used in mining and mineralogy; modern usage prefers simply 'calcite'. The spelling 'calc-spar' also occurs.
Easily confused with calcspar
Feldspar is an aluminosilicate mineral family, whereas calcspar is specifically calcium carbonate (calcite); 'spar' is a general old mining term for any non-metallic crystalline mineral.