Optical petrography and ore microscopy

Zeiss Axioplan 2 petrographic microscope with dedicated AxioCam MRc5 digital camera
Cross-polar photomicrograph showing a silica-carbonate vein in silicified serpentinite
Plane polarised light photomicrograph showing secondary precipitate formation along settling fractures in mine tailings
Reflected light petrographic image showing native copper sheet enclosed beneath layers of red cuprite

Optical microscopy techniques are primary analytical and descriptive tools for the petrographic analysis for all rock types (igneous, metamorphic and sedimentary), as well as unconsolidated materials (e.g. glacial deposits) and anthropogenic materials (e.g. cements and mine wastes). They are also essential for studying mineral deposits (ore minerals) and hydrothermal mineral alteration.

Detailed examination are made of thin sections and polished mounts using optical petrological microscopes, both in transmitted light and reflected light. Information obtained then enables or contributes towards mineral identification, textural analysis, diagenetic phase identification and sequencing, fracture and fault rock studies, modal analysis and porosity characterisation. In addition, UV epifluorescence microscopy is used for microbiological analysis of groundwaters and samples from laboratory experimental studies.

Equipment

  • Research-grade Zeiss Axioplan 2 polarising microscope with bespoke high-resolution digital camera facility, Zeiss AxioVision software for basic image capture and processing and labelling of images.
  • Olympus SZX-10 Stereophotomicroscope equipped with a bespoke high-resolution Peltier-cooled digital camera, Olympus AnalySIS software for basic image capture and processing and labelling of images.
  • Other research-grade Zeiss petrological and binocular microscopes provide multiple user access.
  • Modal analysis using mechanical point counter and microscope stage attachment.
  • Petrographical image analysis for quantitative analysis of mineralogy and fabric using Olympus AnalySIS and other software packages.

Applications

The optical microscope laboratory at Keyworth plays a key role in projects spanning a wide range of the BGS science programme, including:

  • Evaluation fluid-water interaction processes, and characterisation of lithologies and engineered barrier materials intended for radioactive waste disposal and carbon dioxide capture/storage.
  • Natural analogue studies for radioactive waste management and carbon storage.
  • Mineral sequestration of carbon dioxide.
  • Mineral resources, mineral deposits and metallogenesis research.
  • Building stones characterisation and research.
  • Hydrocarbon reservoirs and aquifer properties.
  • Contaminated land and mine waste materials.

Staff and facilities are also in constant demand for direct consultancy analysis and interpretation by external clients including: oil, mineral and mining companies; engineering and utility companies; consultancies; university departments and local authorities.

Contact

Please contact Antoni Milodowski for further information.