Grain mount
Definition
A microscope slide prepared by dispersing sand-grade grains in a mounting medium of known refractive index. Standard forensic grain mounts use Meltmount or Canada balsam (RI ~1.540-1.660). The mounting medium RI affects the contrast of grain edges under PLM.
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...
- Pleochroism
- The property of some minerals (hornblende, tourmaline, biotite) to show different colours when the plane of polarised light rotates relative to the...
- QEMSCAN / MLA
- Automated mineralogy systems (QEMSCAN is from FEI/Thermo Fisher; MLA is the Mineral Liberation Analyser) that combine a scanning electron microscope with automated...
- 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...
Explained in
- Optical Microscopy and Mineral IdentificationA microscope slide prepared by dispersing sand-grade grains in a mounting medium of known refractive index. Standard forensic grain mounts use Meltmount or Can...