Kelvingrove Art Gallery and MuseumDSCF0239 11

In archaeology, a stone ball or petrosphere (from

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

πέτρα (''petra''), "stone", and σφαῖρα (''sphaira''), "ball") is the name for any spherical man-made object of any size that is composed of stone. These mainly prehistoric artifacts may have been created or selected, but altered in some way to perform their specific function, including carving and painting. Alignment Diquis Stone Spheres Museo Nacional CRI 01 2020 1855

Alignment Diquis Stone Spheres Museo Nacional CRI 01 2020 1855

Several classes of petrospheres exist, such as: *the stone spheres of Costa Rica, * painted pebbles from Scotland, *stone charms from Scotland and sandstone balls from such sites as

Traprain Law Traprain Law is a hill east of Haddington, East Lothian, Scotland, It is the site of a hill fort or possibly ''oppidum'', which covered at its maximum extent about . It is the site of the Traprain Law Treasure, the largest Roman silver hoard ...

,Rees, Thomas & Hunter, Fraser (2000). Archaeological excavation of a medieval structure and an assemblage of prehistoric artefacts from the summit of

, East Lothian. 1996 - 7. P.S.A.S. 130, P. 413 - 440. *the carved stone balls, which are mainly from Scotland, although they have also been found in

Cumbria Cumbria ( ) is a ceremonial and non-metropolitan county in North West England, bordering Scotland. The county and Cumbria County Council, its local government, came into existence in 1974 after the passage of the Local Government Act 1972. ...

and

Ireland Ireland ( ; ga, Éire ; Ulster-Scots: ) is an island in the North Atlantic Ocean, in north-western Europe. It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the s ...

, *and carved stone shot for cannons and

trebuchet A trebuchet (french: trébuchet) is a type of catapult that uses a long arm to throw a projectile. It was a common powerful siege engine until the advent of gunpowder. The design of a trebuchet allows it to launch projectiles of greater weigh ...

s. Naturally formed stone balls, such as

concretion A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular ...

s and

spherulite In petrology, spherulites () are small, rounded bodies that commonly occur in vitreous igneous rocks. They are often visible in specimens of obsidian, pitchstone, and rhyolite as globules about the size of millet seed or rice grain, with a d ...

s, have been at times misidentified as petrospheres. For example, fringe archaeologists and advocates of prehistoric extraterrestrial visitors have repeatedly argued that the stone balls, which range in diameter from , found around Cerro Piedras Bola in the Sierra de Ameca, between Ahualulco de Mercado and Ameca, in Jalisco, Mexico, are petrospheres. However, these natural stone balls are megaspherulites that have been released by erosion from a 20- to 30-million-year-old ash flow tuff, which originally enclosed them and in which they formed. The proponents of these stone balls being petrospheres base their arguments on the false claims that all of these spheres are perfectly round, that they are composed of granite, and that natural processes cannot produce stone balls. Similarly, cannonball concretions, i.e. those found along the Cannonball River in

North Dakota North Dakota () is a U.S. state in the Upper Midwest, named after the indigenous Dakota Sioux. North Dakota is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minnesota to the east, ...

and near

Moeraki Moeraki is a small fishing village on the east coast of the South Island of New Zealand. It was once the location of a whaling station. In the 1870s, local interests believed it could become the main port for the north Otago area and a railw ...

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

, New Zealand, also have been misidentified as petrospheres.

Palaeolithic shaped stone balls

Shaped stone balls are found at

Palaeolithic The Paleolithic or Palaeolithic (), also called the Old Stone Age (from Greek: παλαιός ''palaios'', "old" and λίθος '' lithos'', "stone"), is a period in human prehistory that is distinguished by the original development of stone t ...

sites across Africa, Asia, and Europe, associated with

Oldowan The Oldowan (or Mode I) was a widespread stone tool archaeological industry (style) in prehistory. These early tools were simple, usually made with one or a few flakes chipped off with another stone. Oldowan tools were used during the Lower ...

( 2.6 million – 1.7 million years old),

Acheulean Acheulean (; also Acheulian and Mode II), from the French ''acheuléen'' after the type site of Saint-Acheul, is an archaeological industry of stone tool manufacture characterized by the distinctive oval and pear-shaped "hand axes" associate ...

( 1.76 million – 130,000 years old), and African

Middle Stone Age The Middle Stone Age (or MSA) was a period of African prehistory between the Early Stone Age and the Late Stone Age. It is generally considered to have begun around 280,000 years ago and ended around 50–25,000 years ago. The beginnings of pa ...

( 280,000–50,000 years old) stone tool industries. The function of shaped stone balls is still debated. Some archaeologists argue that they were deliberately shaped by humans to use as tools; others that they are byproducts of the use of rocks for other purposes.

References and bibliography

External links

{{Commonscat, Stone spheres
Scottish Stone charms
*Ruffell, W.L., 1996

Royal New Zealand Artillery Old Comrades' Association, New Zealand. *Hoopes, J.W., 2005
The Stone Balls of Costa Rica
University of Kansas, Lawrence, Kansas. *Hunterian Museum and Art Gallery, nd
Carved Stone Balls
A gallery of carved stone ball photographs & information *Marischal Virtual Museum, nd
ball, carved stone
Aberdeen Museum's virtual gallery of their Carved Stone balls *

A Researcher's Guide to Local History terminology A, or a, is the first letter and the first vowel of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''a'' (pronounced ), plural ''aes' ...

Carved Stone Balls of Skara Brae
Archaeological artefact types Lithics Prehistoric art Rock art

Palaeolithic shaped stone balls

See also

References and bibliography

External links