A new photonic material is presented: "photonic glass". This is a 3D completely disordered solid arrangement of monodisperse dielectric spheres (see figure). Monodispersity ensures single-sphere optical resonances to be observed. Very thick (from tenths to few millimetres) uniform samples can be grown by attenuating the inter-sphere interaction. Thin (correlated) disordered films can be grown by vertical convective deposition and selective etching of binary colloidal suspensions.