I've got sort of a specail project going where I put the caulk on something
about the size of a half-dollar coin.

Imagine putting a small bead on the coin's face, then spreading it around
with your finger. What happens of course is the caulk fills in and covers
the small depressions while the higher area's (like the president's face)
you can see still see because your finger sort of "squegees" it off.

Now if I let the caulk cure on the coin for 24hrs what should I find on the
president's face? I would think nothing but there is actually a greasy
residue which I did not expect.

This is 100% silicone: http://www.caulkyourhome.com/sil2_kitchen_bath.html

I rub a blue colored old T-shirt on the raised area's of the coin and it
comes away darker like it was wet or greasy (even after 24hr cure). If I
put a small bead of caulk on a piece of paper (without smearing it) and let
it cure, it looks and feels rubbery like normal caulk with no greasy
residue, even if I pull it away from the paper.

Any thoughts on how this is occuring?