There are actually only 4 marbles in this set (not 21 as stated in the title); 1 × 50mm, 1 × 45mm and 2 × 35mm. In the set I received, the largest marble had a big chip out of it. And disappointingly the marbles are not speckled and brightly coloured as in the photo – they are darker colours and swirls. Not what I expected :(