Service: Thin Section

You might be interested in this service if you:
  • represent a mineral exploration company,
  • are a prospector,
  • are responsible for materials procurement in road construction,
  • are a geologist.
Where samples typically come from
  • mines
  • pit quarries
  • prospector claims
Rock samples-typically cores or individual grab samples, require processing before they can be used for mineral analysis by either PLM (Polarizing Light Microscope, Microprobe and Scanning Electron Microscope/X-ray Microanalysis. The sample has to be thin enough for light to pass through in a light microscope and have a polished surface for electron microscope studies.
This is how we prepare your sample.
  • STEP 1: Cutting a slab
    A suitable size slab for mounting on a slide is cut from a piece of rock or drill core with a diamond saw.
  • STEP 2: Initial Lapping of the Slab
    The slab is labelled on one side and the other side is lapped flat and smooth first on a cast iron lap with 400grit carborundum, then finished on a glass plate with 600 grit carborondum
  • STEP 3: Glass Slide is Added
    After drying on a hot plate, a glass slide is glued to the lapped face of the slab with epoxy. 
  • STEP 4: Slab is sectioned
    Using a thin section saw, the slab is cut-off close to the slide. The thickness is further reduced on a thin section grind. Powders are mixed with expoxy, then spread on a slide and allowed to cure. The surface is ground flat on the thin section grinder, then finished similarly to a thin sections.
  • STEP 5: Final Lapping
    A finished thickness of 30 microns is achieved by lapping the section by hand on a glass plate with 600 grit carborundum. A fine grinding with 1000 grit prior to polishing is optional.
  • STEP 6: Polishing
    The section is placed in a holder and spun on a polishing machine using nylon cloth and diamond paste unitil a suitable polish is achieved for microscope or SEM studies.
  • STEP 7: Final inspection
Download the PDF that shows the steps, complete with photographs.
Need more information?
Anne Hammond
Lakehead University
Geology Department
955 Oliver Rd
Thunder Bay, ON, P7B 5E1
Have questions about this service?
Not sure if this test will help you?
Ready to submit your sample?
Phone: 807-343-8677

LUCAS Lakehead University