Boulder

{{Short description|Natural rock fragment larger than 10 inches}}

{{About|large rocks|the city in Colorado|Boulder, Colorado|other uses}}

Image:Balanced Rock.jpg park in Colorado Springs, Colorado, United States.]]

File:Boulder along the chief hike in Stawamus Chief Provincial Park, BC (DSCF7553).jpg, Canada]]

File:Kämmenkivi stone in Pisa, Kuopio, Finland.jpg, Finland]]

File:Bolders on Mahendra Hills, India.jpg, India.]]

In geology, a boulder (or rarely bowlder){{Cite book |title=Webster's New International Dictionary of the English Language |publisher=G. & C. Merriam Company |year=1913 |location=Springfield, Massachusetts}} is a rock fragment with size greater than {{Convert|25.6|cm|in|1|abbr=on}} in diameter.{{cite book | title=Glossary of Geology | publisher=American Geological Institute | editor-last1=Neuendorf | editor-first1=K.K.E. | editor-last2=Mehl | editor-first2=J.P. Jr. | editor-last3=Jackson | editor-first3=J.A. | year=2005 | location=Alexandria, Virginia | page=79 | isbn=978-0922152896| edition=5th }} Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive.{{cite dictionary|title=Boulder|url=http://dictionary.reference.com/browse/boulder|dictionary=Dictionary.com|access-date=24 August 2013}} In common usage, a boulder is too large for a person to move. Smaller boulders are usually just called rocks or stones.