QEMSCAN / MLA
Definition
Automated mineralogy systems (QEMSCAN is from FEI/Thermo Fisher; MLA is the Mineral Liberation Analyser) that combine a scanning electron microscope with automated EDX analysis of each identified grain. They classify thousands of grains per hour and output mineralogical maps and statistics, enabling high-throughput forensic screening.
- Core technology
- SEM combined with automated EDX analysis
- QEMSCAN vendor
- FEI / Thermo Fisher
- MLA stands for
- Mineral Liberation Analyser
- Throughput
- Thousands of grains classified per hour
- Output
- Mineralogical maps and grain statistics
Common questions
What advantage does QEMSCAN or MLA give over manual optical mineral identification in casework?+
Manual point-counting under a polarising microscope is slow and depends on analyst skill for each grain, while automated mineralogy classifies large populations of grains per sample rapidly and consistently, making bulk soil or trace-mineral comparisons practical within investigative timeframes.
Can QEMSCAN or MLA results alone individualise a soil sample to a specific location?+
No. The mineralogical statistics support comparison and exclusion between an evidence sample and a reference sample, but mineral assemblages can recur across geologically similar sites, so results are typically combined with other trace evidence for a stronger association.
Related terms
- Birefringence
- The difference between the highest and lowest refractive indices of an anisotropic mineral, seen as a characteristic interference colour between crossed polars....
- Extinction Angle
- The angle, measured in degrees on the rotating stage of a petrographic microscope, between a crystallographic reference direction (cleavage trace or crystal...
- Grain Mount
- A microscope slide prepared by dispersing sand-grade grains in a mounting medium of known refractive index. Standard forensic grain mounts use Meltmount...
- Pleochroism
- The property of some minerals (hornblende, tourmaline, biotite) to show different colours when the plane of polarised light rotates relative to the...
- SEM-EDX
- Scanning electron microscopy with energy-dispersive X-ray spectroscopy. The electron beam excites characteristic X-rays from each element present in the target grain, giving...