Full Idea
Yablo proposes the argument that Statue A is essentially a statue, and Lump 1 is not essentially a statue, so Statue A is not identical with Lump 1.
Gist of Idea
A statue is essentially the statue, but its lump is not essentially a statue, so statue isn't lump
Source
report of Stephen Yablo (Identity, Essence and Indiscernibility [1987]) by Michael della Rocca - Essentialists and Essentialism I
Book Reference
-: 'Journal of Philosophy' [-], p.190
A Reaction
Della Rocca and Yablo unashamedly elide necessary properties with essential properties, so this argument doesn't bother me too much. It concerns the statue and the clay having different modal properties.