Novaculite, also called Arkansas Stone, is a

microcrystalline A microcrystalline material is a crystallized substance or rock that contains small crystals visible only through microscopic examination. There is little agreement on the range of crystal sizes that should be regarded as microcrystalline, but ...

cryptocrystalline Cryptocrystalline is a rock microstructure, rock texture made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically in thin section by transmitted polarized light. Among the sedimentary rocks, chert a ...

rock type that consists of

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant f ...

in the form of

chert Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a prec ...

flint Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely used to make stone tools and start ...

. It is commonly white to grey or black in color, with a

specific gravity Relative density, also called specific gravity, is a dimensionless quantity defined as the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for solids and liquids is nea ...

that ranges from 2.2 to 2.5. It is used in the production of

sharpening stone Sharpening stones, or whetstones, are used to sharpening, sharpen the edges of steel tools such as knife, knives through grinding and Honing (metalworking), honing. Such stones come in a wide range of shapes, sizes, and material compositions. ...

s. It occurs in parts of

Arkansas Arkansas ( ) is a landlocked state in the West South Central region of the Southern United States. It borders Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, Texas to the southwest, and Oklahoma ...

Oklahoma Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...

, and

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

, as well as in

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

and parts of the

Middle East The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula, the Levant, Turkey, Egypt, Iran, and Iraq. The term came into widespread usage by the United Kingdom and western Eur ...

. The name ''novaculite'' is derived from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

word ''novacula'', meaning a sharp knife, dagger, or razor, in reference to its use in sharpening. The first recorded use of the term '' whetstone'' was in reference to a honing stone from Arkansas.

Occurrence

Novaculite beds are present in the

Ouachita Mountains The Ouachita Mountains (), simply referred to as the Ouachitas, are a mountain range in western Arkansas and southeastern Oklahoma. They are formed by a thick succession of highly deformed Paleozoic strata constituting the Ouachita Fold and Thru ...

and

, and in the

Marathon Uplift The Marathon Uplift is a Paleogene-age domal uplift, approximately in diameter, in southwest Texas. The Marathon Basin was created by erosion of Cretaceous and younger strata from the crest of the uplift.McBride, E.F. and Hayward, O.T., 1988''Geo ...

and Solitario regions of

. Novaculite is very resistant to

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

and the beds stand out as ridges in the Ouachita Mountains. There are also occurrences in

Syria Syria, officially the Syrian Arab Republic, is a country in West Asia located in the Eastern Mediterranean and the Levant. It borders the Mediterranean Sea to the west, Turkey to Syria–Turkey border, the north, Iraq to Iraq–Syria border, t ...

Lebanon Lebanon, officially the Republic of Lebanon, is a country in the Levant region of West Asia. Situated at the crossroads of the Mediterranean Basin and the Arabian Peninsula, it is bordered by Syria to the north and east, Israel to the south ...

, and

Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...

Origin

The novaculite beds of the south-central United States were deposited in the Ouachita Geosyncline, a deep-water marine trough, during

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

to early Mississippian time. Sedimentation consisted primarily of

siliceous Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant ...

skeletal particles of marine organisms such as

sponge spicule Spicules are structural elements found in most sponges. The meshing of many spicules serves as the sponge's skeleton and thus it provides structural support and potentially defense against predators. Sponge spicules are made of calcium carbo ...

s and

radiolaria The Radiolaria, also called Radiozoa, are unicellular eukaryotes of diameter 0.1–0.2 mm that produce intricate mineral skeletons, typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ect ...

, and very fine-grained, wind-blown

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

particles; there was very little

argillaceous Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al2 Si2 O5( OH)4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay mineral ...

sedimentation during novaculite deposition.McBride, E.F. and Thomson, A. 1970. The Caballos novaculite, Marathon region, Texas. Geological Society of America, Special Paper 122, 129. p. The novaculite beds were later subjected to folding and uplift, and probably low-grade

metamorphism Metamorphism is the transformation of existing Rock (geology), rock (the protolith) to rock with a different mineral composition or Texture (geology), texture. Metamorphism takes place at temperatures in excess of , and often also at elevated ...

, during the Ouachita orogeny in early Pennsylvanian time.

Use

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Because novaculite is very hard and dense, it has been mined since prehistoric times, first for use as arrow and spear points, and later to make sharpening stones. Novaculite-rich sharpening stones from Arkansas are called ''Arkansas stones''; stones produced in the

Ottoman Empire The Ottoman Empire (), also called the Turkish Empire, was an empire, imperial realm that controlled much of Southeast Europe, West Asia, and North Africa from the 14th to early 20th centuries; it also controlled parts of southeastern Centr ...

(Syria, Lebanon, and Israel) were called ''Turkey stones''; and novaculite stones were also produced in Japan. The crystal grains of novaculite measure 3 to 5 microns, equivalent to a US grit size of 600-1200, making novaculite suitable for the final stages of metal blade sharpening. Novaculite sharpening stones are classified by density.https://danswhetstone.com/information/selecting-your-whetstone/ The weathered upper strata of Arkansas novaculite, known as

tripoli Tripoli or Tripolis (from , meaning "three cities") may refer to: Places Greece *Tripolis (region of Arcadia), a district in ancient Arcadia, Greece * Tripolis (Larisaia), an ancient Greek city in the Pelasgiotis district, Thessaly, near Larissa ...

or "rotten stone", are rich in silica and have found a niche market as a performance additive or filler in the coatings, adhesives, sealants, and

elastomer An elastomer is a polymer with viscoelasticity (i.e. both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus (E) and high failure strain compared with other materials. The term, a portmanteau of ''ela ...

industries. Tripoli is mined just east of

Hot Springs, Arkansas Hot Springs is a resort city in the state of Arkansas and the county seat of Garland County, Arkansas, Garland County. The city is located in the Ouachita Mountains among the U.S. Interior Highlands, and is set among several natural hot springs ...

by the Malvern Minerals Company.Nichols, John C., ''Minerals on the Ouachita National Forest,'' USDA Forest Service 12 May 2008
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References

{{Reflist * Folk, R.L., and E.F. McBride, 1976, ''The Caballos Novaculite revisited Part I: Origin of novaculite members''. Journal of Sedimentary Petrology. 46:659-669. * Folk, R.L., and E.F. McBride, 1978, ''Origin of the Caballos Novaculite''. in S.J. Mazzullo, ed., Tectonics and Paleozoic facies of the Marathon Geosyncline, West Texas: Permian Basin Section, Society for Sedimentary Geology, SEPM, Publication no. 78-17:101-130. * Frondel, C., 1962, ''The System of Mineralogy of J. D. and E. S. Dana, v. 3, Silica Minerals'': 7th ed., John Wiley and Sons, New York, 334p. * King, P.B., 1937

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

Professional Paper 187 * Krumbein, W.C., and Sloss, L.L., 1963, ''Stratigraphy and Sedimentation'': 2nd ed., W. H. Freeman and Company, San Francisco, 660p. * Lowe, D.R., 1975, ''Regional Controls on Silica Sedimentation in the Ouachita System''.

Geological Society of America The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hi ...

Bulletin. 86:1123-1127 * Lowe, D.R., 1976, ''Nonglacial varves in lower member of Arkansas Novaculite (Devonian), Arkansas and Oklahoma''.

American Association of Petroleum Geologists The American Association of Petroleum Geologists (AAPG) is one of the world's largest professional geological societies with about 17,000 members across 129 countries. The AAPG works to "advance the science of geology, especially as it relates to ...

Bulletin. 60:2103-2116. * Lowe, D.R., 1977, ''The Arkansas novaculite: some aspects of its physical sedimentation''. in C.G. Stone, and others, eds., Symposium on the geology of the Ouachita Mountains. Arkansas Geological Commission Miscellaneous Publication 13:132-138. * Lowe, D.R., 1989, ''Stratigraphy, sedimentology, and depositional setting of pre-orogenic rocks of the Ouachita Mountains, Arkansas and Oklahoma'', in R.D. Hatcher, Jr., W.A. Thomas, and G.W. Viele, eds., The Appalachian-Ouachita orogen in the United States. The Geology of North America. F-2:575-590, Geological Society of America, Boulder. * McBride, E.F., 1989, ''Stratigraphy and sedimentary history of Pre-Permian Paleozoic rocks of the Marathon uplift'', in R.D. Hatcher, Jr., W.A. Thomas, and G.W. Viele, eds., The Appalachian-Ouachita orogen in the United States. The Geology of North America. F-2:603-620, Geological Society of America, Boulder.

External links

Arkansas Geological Commission: ''Novaculite''

* ttps://web.archive.org/web/20201110020239/http://archeology.uark.edu/novaculite/index.html Arkansas Archeological Survey: ''Arkansas Novaculite: A Virtual Comparative Collection'' Minerals Economic geology Industrial minerals Ouachita Mountains Sedimentary rocks Chert