Stone ball

A stone ball, or "stone sphere", is a spherical stone object that may be of either natural or artificial origin. Different types of stone balls include:

Natural

• Natural Stone Balls
  • megaspherulites
  • cannonball concretions
    • Moeraki Boulders
    • Rock City, Kansas
  • Moqui marbles
  • spherical corestones created by spheroidal weathering

Artificial

• Artificial Stone Balls (Petrospheres)
  • lapidary spheres
  • Lithic-Bolas
  • stone round shot (cannonballs)
    • Ammunition column
  • spherical stone shot for trebuchets
  • Stone spheres of Costa Rica
  • Carved Stone Balls of Scotland
• Kugel balls

External links

Stone round shot (cannonballs)

• Ruffell, W.L., 1996, The Gun - Smoothbore Era 1550-1860: Projectiles Royal New Zealand Artillery Old Comrades' Association, New Zealand.

Stone balls (spheres) of Costa Rica

• Hoopes, J.W., 2005, The Stone Balls of Costa Rica University of Kansas, Lawrence, Kansas.

Carved stone balls of Scotland

• 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

Megaspherulites

• Baird, Bill, 1990, Stone Spheres, The Edinburgh Geologist, no 24 (Spring)
• Heinrich, P.V., 2007, PDF version, 1.4 MBMegaspherulites. BackBender's Gazette. vol. 38, no. 7, pp. 8-12.
• Rodríguez, E.A., 2002, The fantastic balls in el Cerro Piedras Bola (Jalisco), México desconocido # 305, July 2002. Last visited February 11, 2008.
• Smith, R.K., R.L. Tremallo, and G.E. Lofgren, 2000, Megaspherulite Growth: Far From Equilibrium Crystallization, GeoCanada 2000 - The Millennium Geoscience Summit, Canadian Society of Exploration Geophysicists Annual Meeting.
• Smith, R.K., R.L. Tremallo, and G.E. Lofgren, 2001, Growth of megaspherulites in a rhyolitic vitrophyre, American Mineralogist. vol. 86, pp. 589–600.

Cannonball concretions

• Hanson, W.D., and J.M. Howard, 2005, PDF version, 2.8 MBSpherical Boulders in North-Central Arkansas Arkansas Geological Commission Miscellaneous Publication n. 22, pp. 1-23.
• Heinrich, P.V., 2007, PDF version, 836 KBThe Giant Concretions of Rock City Kansas BackBender's Gazette. vol. 38, no. 8, pp. 6-12.
• Irna, 2006, All that nature can never do, part IV : stone spheres
• Irna, 2007a, Stone balls : in France too!
• Irna, 2007b, Stone balls in Slovakia, Czech Republic and Poland
• Leo Gav, 2007, Underwater stone balls
• Hokianga Tourism Association, nd, Koutu boulders Really nice pictures of cannonball concretions.
• United States Geological Survey, nd, cannonball concretion