ASTM E3294

Forensic Analysis of Geological Materials by Powder X-Ray Diffraction

Applicability: ASTM E3294 applies to geological materials submitted as forensic evidence, including soils, sediments, rock fragments, minerals, and mixed geological samples collected from crime scenes, clothing, vehicles, or other evidentiary contexts. It covers the use of powder X-ray diffraction (XRD) for mineralogical characterization of these materials in accredited forensic science laboratories. The guide applies to both qualitative phase identification and semi-quantitative or quantitative phase analysis of geological evidence.

Purpose: ASTM E3294 establishes best practices for the forensic analysis of geological materials using powder XRD, encompassing sample preparation, instrument calibration, data collection, phase identification using reference databases (such as ICDD PDF), and the defensible reporting of results. Mineralogical profiles obtained by XRD can link geological evidence to specific source locations, establish associations between persons of interest and crime scenes, and support soil comparison testimony in criminal and civil proceedings; the guide provides a standardized framework to ensure that analytical results are scientifically reproducible, technically valid, and admissible in legal proceedings.