Identification and composition analysis of small grains
Backscattered electron image of a sample of the Merensky UG 2 chromitite layer from South Africa. It shows abundant grains of chromite - a chromium-iron oxide mineral - as grey. Paler grey areas are iron and nickel sulfide minerals. Scalebar = 2mm.
The Zeiss EVO 15LS scanning electron microscope can be used to:
- locate specific small grains of interest in large sample areas
- measure their size
- identify their composition
In this example the Zeiss EVO 15LS was used to find micrometre-scale grains of valuable platinum group elements in a sample of the Merensky UG 2 chromitite layer from South Africa. Although they should be very bright in a backscattered electron image, they are not easily seen.
The microscope was programmed using automated feature recognition and analysis routines. Searching across several hundred areas, it found many tiny, bright grains and measured the chemical composition of each. Many contained platinum-group metals.