These earrings show two special mathematical objects --- the complete graph on five vertices (K_5) and the complete bipartite graph with six vertices (K_{3,3}). Together they give complete information about when a graph can be drawn on paper without crossings. This is known as
Kuratowski's Theorem.
If you prefer a matching pair, consider these alternatives:
Complete Graph Earrings
Complete Bipartite Graph Earrings
Aspiring Graph Theorists will also be interested in the matching
Petersen Graph Pendant