a.k.a. Cuboctahedron
Designed by Steve and Leslie Smith, made and sold by Interlocking Puzzles 2004;
box made by J. A. Storer 2004.
(5 pieces: Jatoba, 4.5 inches,
6 pieces: Peroba Rosa, 4.5 inches,
7 pieces: Jarrah, 4.5 inches,
box is 3/8 inch plexiglass with metal hardware, 5 by 5 by 12 inches)

These three puzzles have the same size and shape, with six square faces and eight triangular faces (corresponding to where the corners of the cube have been truncated). The five piece version was designed by Steve Smith and the 6 and 7 piece versions by Steve and Leslie Smith. Here is some of what they say about these three puzzles:

Five piece Truncated Cube: "Each piece is a challenge, even after removing the first three, getting the last two apart and together isn't easy. Reassembly? Let's just say this should NOT be the first polyhedra puzzle of ours you work with."

Six piece Truncated Cube: "A small internal space requires multiple moves to get the first piece out."

Seven piece Truncated Cube: "Unique trilateral symmetry makes this puzzle quite difficult. This puzzle can be thought of as two three piece puzzles, with a key piece that holds it all together."