Crystal graphs provide combinatorial tools to study the representation theory of Lie algebras. In this talk, I will discuss joint work with Sylvie Corteel, Zajj Daugherty and Anne Schilling investigating the (Type A) crystal skeleton, which is a graph obtained by contracting certain components of a crystal graph. On the level of characters, crystal skeletons model the expansion of Schur functions into Gessel's fundamental quasisymmetric functions. Motivated by questions of Schur positivity, we provide a combinatorial description of crystal skeletons, and prove many new properties, including a conjecture by Maas-Gari'epy that crystal skeletons generalize dual equivalence graphs. We then characterize the crystal skeleton axiomatically, in analogy to the Stembridge axioms for crystals.