Novaculite, also called Arkansas Stone, is a
microcrystalline to
cryptocrystalline rock type that consists of
silica in the form of
chert or
flint. It is commonly white to grey or black in color, with a
specific gravity that ranges from 2.2 to 2.5. It is used in the production of
sharpening stones. It occurs in parts of
Arkansas,
Oklahoma, and
Texas, as well as in
Japan and parts of the
Middle East. The name novaculite is derived from the
Latin word novacula, meaning a sharp knife, dagger, or razor,[2] in reference to its use in sharpening. The first recorded use of the term whetstone was in reference to a honing stone from Arkansas.[3]
The novaculite beds of the south-central United States were deposited in the
Ouachita Geosyncline, a deep-water marine trough, during
Silurian to early
Mississippian time. Sedimentation consisted primarily of
siliceous skeletal particles of marine organisms such as
sponge spicules and
radiolaria, and very fine-grained, wind-blown
quartz particles; there was very little
argillaceous sedimentation during novaculite deposition.[5] The novaculite beds were later subjected to folding and uplift, and probably low-grade
metamorphism, during the
Ouachita orogeny in early
Pennsylvanian time.[1]
Use
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;[6] stones produced in the
Ottoman empire (Syria, Lebanon, and Israel) were called Turkey stones;[4] and novaculite stones were also produced in Japan.[4]
The weathered upper strata of Arkansas novaculite, known as
tripoli 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 industries. Tripoli is mined just east of
Hot Springs, Arkansas by the Malvern Minerals Company.[3]
Folk, R.L., and E.F. McBride, 1976, The Caballos Novaculite revisited Part I: "origin of novaculite members . Journal of Sedimentary Petrology. 46659-669
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.
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 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 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.