GeomBlocks T/O is a modular construction set for building shapes in tetrahedral / octahedral geometry.
One way to tile space is with cubes. But that's not the only way. Regular tetrahedra and octahedra also tile space, in an alternating honeycomb pattern. (They can also build larger copies of themselves!)
In GeomBlocks T/O, the tetrahedra have connectors that plug into the octahedra -- and half octahedra, which also turn out to be useful.
This basic set consists of 18 each of half octahedra and two-connector tetrahedra, and 4 each of octahedra, one-, three-, and four-connector tetrahedra. The unit edge length is 20mm.
Use GeomBlocks to explore the mathematics of tessellations, build geometric sculpture, or design puzzles outside the same old cubic landscape. (Complex puzzles might require multiple sets. Some of the photos show multiple sets in multiple colors.)