Marbles of different sizes and colors.
<a rel="nofollow" class="external text" href="http://tools.wikimedia.de/~daniel/WikiSense/Gallery.php?wikifam=commons.wikimedia.org&amp;wikilang=en&amp;order=-img_timestamp&amp;img_user_text=Jorgebarrios&amp;ofs=0&amp;max=250">Jorge Barrios</a>
Trabjo propio.