Existence of a complexity threshold for mineral biosignatures or technosignatures

Determine whether a well-defined threshold in material complexity exists such that, when exceeded by a mineral, the mineral can be classified as a biosignature or technosignature.

Background

Inspired by molecular assembly serving as a biosignature, the authors compute assembly indices for thousands of mineral unit cells and find no apparent threshold in the data, highlighting a gap in distinguishing evolved or engineered materials from naturally formed ones.

They explicitly note that it remains unknown whether a complexity threshold for minerals could serve as a biosignature or technosignature. Subsequent theoretical considerations suggest that engineered structures may surpass random ones in measurable assembly, motivating experimental tests.