Comment by gus_massa

Slightly related: In a stone shop nearby my home they sell a nice set of Platonic Solids made of semitransparent stones, but the octahedron is an irregular one :((( It's very similar to the ser in this photo https://www.mercadolibre.com.ar/solidos-platonicos-geometria... It's a nice present for a friend that is a mathematician too, but there is high chance that they will notice.