The qualitative and quantitative properties of ore minerals are studied in the Museum's reflected light microscopy and microscope spectrophotometry laboratory.
Mineral characterisation plays an important role in generating new mineral descriptions and in consultancy projects.
Ore minerals such as sulphides, sulphosalts and oxides are examined in polished blocks or thin sections to determine their qualitative properties (mineral identification, grain relationships, textures) and their quantitative properties (reflectance, microhardness).
The late Alan Criddle established the laboratory at the end of the 1970s. Initially it contained a microscope equipped with a line interference filter measuring at 10nm intervals in the visible spectrum from 400 to 700nm.
The Museum acquired an instrument with a grating monochromator in the 1990s, and a J & M Tidas diode array spectrometer in 2006. These have been used to gather optical data on more than 120 new minerals and produce the 2nd and 3rd issues of the Quantitative Data File for Ore Minerals, edited by A J Criddle and C J Stanley, 1984 and 1993.
An updated database of optical data is available online for the four wavelengths (470nm, 546nm, 589nm, and 650nm) recommended by the Commission on Ore Mineralogy of the International Mineralogical Association.
View a selection of images produced by the ore mineralogy lab. More images are being digitised and a full archive will be available soon.