Geochempet employs a variety of experimental techniques to deliver quantitative data to clients on the mineralogical and elemental composition of bulk samples, as well as small (micron-scale) features within them. For XRD and Geochemical Analysis, samples will be milled and homogenised to fine powder to give representative bulk average data. Scanning electron microscope specimens for rough reconnaissance work may be dabs of powder, but for quantitative analysis are either small polished slabs or uncovered polished thin sections prepared from the original sample, in which square-millimetre regions of interest can be examined in detail.
Quantitative XRD ± Clay Analysis
Percentages of major minerals (detection limit ~ 1%) and of overall “amorphous content” by powder X-ray diffraction and Rietveld fitting. Fitted experimental data and interpretation provided by us as part of the report. The additional ‘Clay Analysis’ option also includes separation of clay-sized fraction from a subsample, identification clay species present and their qualitative abundance.
Geochemical Analysis
Clients most commonly request analysis of bulk composition, including major and minor chemical elements using X-ray fluorescence spectroscopy, along with a general estimate of volatile content through loss-on-ignition. Results are accompanied by Geochempet’s interpretation, which may include comparisons with petrographic or XRD findings from the same sample.
A range of other options are available on request, including carbonate and/or organic content determination, and trace elements by other techniques such as ICP-MS or ICP-OES of digested samples, including variants with specialised sample preparation methods for precious metals.
Scanning Electron Microscopy
Use of analytical scanning electron microscope for submicron-resolution imaging of surfaces and/or EDS elemental analysis of major chemical elements from micron-scale spots or traverses. Applications include verification of habit and mineral identity for asbestiform materials, mineral composition and identification for metallic ore minerals, cement micromineralogy including degradation and fracture fill phases. Additional options include multi-element X-ray mapping to locate concentrations of elements of interest and visualise their distribution.
Transmission Electron Microscopy
Nanoscale imaging of crushed-grain mounts or thinned wafers from a sample, with electron diffraction from submicron spots for Identification and or orientation of individual particles.