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Spar is an old mining or mineralogy term used to refer to crystals that have readily discernible faces. A spar will easily break or cleave into rhomboidal, cubical, or laminated fragments with smooth shiny surfaces.

The various spar minerals were a historical term among miners and alchemists for any nonmetallic mineral akin to gypsum, known in Old English as spærstān, spear stone, referring to its crystalline projections. Thus, the word spar in mineralogy has the same root as "spear,".

Amongst miners the term "spar" today is frequently used alone to express any bright crystalline substance. Most frequently, spar describes easily cleaved, lightly colored nonmetallic minerals such as feldspar, calcite or baryte. Baryte (Ba S O₄), the main source of barium, is also called "heavy spar" (Greek "barys" means "heavy"). Calcite often forms the dogtooth spar crystals found in vugs and caves.

Formation underwater

Generally, a spar will form underwater, either in a phreatic zone, or below the water table, the essential place where most caves form, or in standing pools, as pool spar.^[1] If a cave floods and a pool forms, that submerges stalactites, a formation known as bottlebrushes may form.^[2] Mineral component ions dissolved in water are mostly deposited as minerals such as calcite and gypsum, and sometimes even halite, quartz, and fluorite, through the course of thousands of years, building up on each other.

Formation in the air

Sometimes, spar will form in the air due to solutions seeping out of the cave's walls or through porous sediments. When grown in the air, it is often made of gypsum or selenite. Sometimes it will form as small needles found in sediments. Other spars can be found on the tips of gypsum chandeliers.

References

^ Bunnell, Dave. "Pool spar". The virtual cave. Retrieved 8 December 2013.
^ Bunnell, Dave. "Bottlebrushes". The virtual cave. Retrieved 8 December 2013.

External links

Virtual cave tour

[1] Bunnell, Dave. "Pool spar". The virtual cave. Retrieved 8 December 2013.

[2] Bunnell, Dave. "Bottlebrushes". The virtual cave. Retrieved 8 December 2013.

[1]

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+{{Short description|Crystal that has readily discernible faces}}
-{{otheruses|Spar (disambiguation)}}
+[[File:Calcite, fluorine.jpg|thumb|Dogtooth spar with fluorite from the Elmwood Mine in Tennessee]]
-'''Spar''' is a term that is used to refer to a category of crystals that have readily discernible faces. [[crystal|Crystallized]], earthy, and some [[metallic]], a spar will easily break into [[rhomboid|rhomboidal]], [[cube|cubical]], or [[laminated]] fragments with polished surfaces, but without regard to the ingredients of which they are composed. Amongst [[miner]]s the term is frequently used alone to express any bright crystalline substance. {{Fact|date=March 2007}} [[Image:Poolspar.jpg|thumb|250px|A pool spar]]Most frequently, spar describes easily cleaved, lightly colored  nonmetallic minerals such as [[feldspar]], [[calcite]] or [[barite]].<ref>http://www.minerals.net/mineral/extended/spar.htm</ref> Barite ([[Barium|Ba]][[Sulfur|S]][[Oxygen|O]]<sub>4</sub>), the main source of [[barium]], is also called "heavy spar" ([[Greek language|Greek]] "barys" means "heavy").
+'''Spar''' is an old mining or mineralogy term used to refer to [[crystal]]s that have readily discernible faces. A spar will easily break or [[cleavage (mineralogy)|cleave]] into [[rhomboid]]al, [[cube|cubical]], or [[laminated]] fragments with smooth shiny surfaces.
-The largest type of spar is of the phreatic variety, since it essentially much more time to grow than average spar. It grows best where the water is just barely saturated with minerals. Some caves are like giant [[geode]]s, the walls and ceilings completely lined with spar. [[Jewel Cave]] and others in the [[Black Hills]] of [[South Dakota]] contain large quantities of spar.<ref>http://www.goodearthgraphics.com/virtcave/spar/spar.html</ref>
+The various spar minerals were a historical term among miners and alchemists for any nonmetallic mineral akin to [[gypsum]], known in Old English as spærstān, ''spear stone'', referring to its crystalline projections. Thus, the word spar in mineralogy has the same root as "spear,".
-==Formation==
-Generally, a spar will form underwater, either in a [[phreatic|phreatic zone]], or below the [[water table]], the essential place where most caves form.{{Fact|date=March 2007}}  Minerals in the water, mostly [[calcite]] or [[gypsum]], but sometimes even [[halite]], [[quartz]], and [[fluorite]], are deposited through the course of thousands of years, building up on each other.[[Image:Ballroom9.jpg|thumb|250px|A [[gypsum]] chandelier, a type of spar]]
+Amongst [[miner]]s the term is frequently used alone to express any bright crystalline substance.  Most frequently, spar describes easily cleaved, lightly colored  nonmetallic minerals such as [[feldspar]], [[calcite]] or [[]].  ([[Barium|Ba]][[Sulfur|S]][[Oxygen|O]]<sub>4</sub>), the main source of [[barium]], is also called "heavy spar" ([[Greek language|Greek]] "barys" means "heavy").
-==Growth in the Air==
+Calcite often forms the [[dogtooth spar]] crystals found in [[vug]]s and [[cave]]s.
+==Formation==
-Sometimes,  spar will form in the air due to [[solution]]s seeping out of the cave's walls or through porous sediments. When grown in the air, it is often made of [[gypsum]] or [[selenite]]. Sometimes it will form as small needles found in sediments. Others spar can be found on the tips of [[gypsum]] chandeliers.
+Generally, a spar will form underwater, either in a [[phreatic|phreatic zone]], or below the [[water table]], the essential place where most caves form, or in standing pools, as pool spar.<ref>{{cite web|last=Bunnell|first=Dave|title=Pool spar|url=http://www.goodearthgraphics.com/virtcave/poolspar/poolspar.html|work=The virtual cave|accessdate=8 December 2013}}</ref> If a cave floods and a pool forms, that submerges [[Stalactite|stalactites]], a formation known as [[Bottlebrushes (Cave Formation)|bottlebrushes]] may form.<ref>{{cite web|last=Bunnell|first=Dave|title=Bottlebrushes|url=http://www.goodearthgraphics.com/virtcave/bottlebr/bottlebr.html|work=The virtual cave|accessdate=8 December 2013}}</ref>   Mineral component ions dissolved in water are mostly deposited as minerals such as [[calcite]] and [[gypsum]], and sometimes even [[halite]], [[quartz]], and [[fluorite]], through the course of thousands of years, building up on each other.
-== Pool Spar ==
+==   ==
+Sometimes, spar will form in the air due to [[solution]]s seeping out of the cave's walls or through porous sediments. When grown in the air, it is often made of [[gypsum]] or [[selenite]]. Sometimes it will form as small needles found in sediments.   can be found on the tips of [[gypsum]] chandeliers.
-Pool spar are well-defined [[crystals]] that grow underwater in pools, and are a subtype of spar crystal, usually composed of [[calcite]]. {{Fact|date=March 2007}} Often the pool in which the crystals grew has evaporated, or fills only seasonally. Pool spar is often found on the bottom of [[shelfstone]].
+== See also ==
-Most pool spar is nicknamed "dogtooth" because of the fact that it comes to a jagged point. Other pool spar, especially ones formed along the flat surface of the pool, may even form in a triangular shape.
+*[[Iceland spar]]
 == References ==
+{{reflist}}
-<references/>
-[[es:espato]]
-== See Also ==
+==   ==
-*[[Cave]]
-*[[Mineral]]
-*[[Mineralogy]]
-== External Links ==
 *[http://www.goodearthgraphics.com/virtcave/spar/spar.html Virtual cave tour]
+[[Category:Crystals]]
 [[Category:Mineralogy]]
+[[Category:Cave geology]]