After a rock is rounded, then also weathering is going to affect it. Although the rocks with rough angles get weathered more quickly, but still a rounded rock will ultimately start weathering and becoming smaller in size. Weathering can not only alter the rock physically, but it can also alter the rounded rock chemically depending on the material by which it is made of. Biological weathering can always weather away a rock without depending on its shape or size. There are other forms of weathering also that can impact the rounded rock.