colloidal crystal

https://doi.org/10.1351/goldbook.13803
Two- or three-dimensional ordered array of molecules or nanoparticles having a dimension roughly between \(\pu{1 nm}\) and \(\pu{1 \upmu m}\) in at least one direction.
Example: Colloidal crystals are photonic crystals such as opal.
Source:
PAC, 2012, 85, 463. (Terminology for aggregation and self-assembly in polymer science (IUPAC Recommendations 2013)) on page 467 [Terms] [Paper]