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Question: does a grain mean the same thing in geology as it does in Material science? If so, a grain 10 inches in diameter seems impossibly large! I would not expect to find this naturally (Neutron Stars, etc. notwithstanding). (talk) - 15:27, 21 October 2009 (UTC)[reply]

"Grain" is used not in the sense of grains in metals or crystal but in the sense of grains in granular materials like clay, sand, gravel, etc. mike4ty4 (talk) 00:39, 24 January 2010 (UTC)[reply]
I also think that "grain size" for rock and boulder is not applicable in common language. May be for scientific use it is OK, but it is just funny to read in a lexicon... I corrected it. — Preceding unsigned comment added by JSoos (talkcontribs) 17:37, 6 July 2015 (UTC)[reply]
'Clast size' is probably a better term, although I see that Wentworth's original 1922 paper also refers to 'fragments' or 'pieces'. However, 'grain size' is the term typically used for sediments or rocks. Mikenorton (talk) 20:56, 6 July 2015 (UTC)[reply]

Size distinction[edit]

I question the statement "In British English a rock is bigger than a boulder" Neither the Cambridge Dictionary (https://dictionary.cambridge.org/dictionary/english/rock), the Macmillan Dictionary (https://www.macmillandictionary.com/dictionary/british/boulder) or the Dictionary linked in the sources (https://www.dictionary.com/browse/rock) give reason to believe that. Just the opposite, the first two dictionaries define a boulder as "a very large rock" (https://dictionary.cambridge.org/dictionary/english/boulder & https://www.macmillandictionary.com/dictionary/british/boulder) which to me is the opposite of the statement in question. 2003:C9:672B:9F59:3C4A:50D5:A78D:21E (talk) 21:40, 27 June 2020 (UTC)[reply]

I suggest removing the statement at this point. Tankpiggy18 (talk) 17:06, 10 April 2022 (UTC)[reply]

I founnd the statement that a boulder is a rock fragment with size greater than 25.6 cm (10.1 in) in diameter surprising though it apparently has a source - on looking back though, this started as 256mm / 10 inches which makes more sense - yet another example of the conversion template producing nonsense. Can it be fixed by someone familiar with these things? Geopersona (talk) 05:23, 23 March 2024 (UTC)[reply]