New research shows that it is possible to classify rocks according to the size of the particles they contain during quarrying by using a portable Raman spectrometer.
The nature and potential uses of a sedimentary rock depends on the size of the particles or grains that they are composed from and particle sizing is an important part of rock classification.
A group of researchers led by IacopoOsticioli of Istituto di FisicaApplicata N. Carrara, Florence, Italy has shown that it is possible to size particles and identify rock samples rapidly and accurately while they are being quarried using a portable Raman spectrometer.
Limestone is a sedimentary and calcareous rock. This is made up principally of calcite and other minority minerals with variable grain dimensions. Each type produces a different quality of quicklime for specific industrial applications. It can be classified according to the sizes of the grains it is composed of. Each type has a different range of industrial uses.
Previous research has shown that the intensity of Raman spectral signals will depend on the particle or granule sizes of the sample tested. Osticioli and his co-workers set out to quantize this effect and to use the information to see whether it would be possible to classify rocks in situ.
They examined a set of rock samples that had been classified by experts. It showed that there was a clear correlation between Raman signal and particle size. The apparatus is portable and small enough to be used during quarrying, and it produces results rapidly.