Biometriet

Biometriet is a hypothetical class of biomineral composites defined as mineral-like aggregates formed through microbial activity. The term blends biology with mineralogical concepts and is used in speculative discussions about how life can shape inorganic structures in ways that resemble meteoritic textures. In this framework, biometriet is not a widely accepted natural mineral, but a conceptual category for studying life–mineral interactions and their potential signatures.

Formation and characteristics of biometriet are described as processes in which microorganisms catalyze and organize mineral precipitation. Extracellular polymeric substances (EPS) produced by communities can template mineral grains, while redox reactions and local chemistry steer phase selection, grain size, and porosity. Typical components proposed in biometriet models include iron- and manganese-rich oxides and carbonates, silica, and carbon-rich organic matter. The resulting textures are envisioned as multi-phase, nano- to microscale aggregates that may exhibit meteoritic-like microstructures, such as zoned grains or cohesive matrices that trap organics.

Occurrence and study of biometriet are primarily in laboratory simulations and terrestrial analog environments, such as hydrothermal systems or saline lakes, where conditions resemble those speculated for early Earth or other planetary bodies. There is no documented, uncontested natural occurrence of biometriet in meteorites, and the concept remains a theoretical tool for exploring biosignatures and rock-forming processes under biological influence. Researchers investigate biometriet to understand how life could imprint recognizable mineral signatures and how such signatures might be distinguished from abiotic mineralization.

Significance and debate: biometriet serves as a framework for discussing biosignatures in geology and astrobiology, but its hypothetical status invites scrutiny regarding reproducibility and differentiation from non-biological processes. Ongoing work focuses on developing robust criteria to identify genuine biometriet-like signatures in experimental, Earth-analog, and planetary contexts.