The Dorothy Urlich-Cloher School of Environment

Earth Science Processing Lab

The Earth Science Processing Lab (ESP Lab) is a recently commissioned space that allows the preparation of rock, soils and wood samples for both teaching and research.

Thin section of rock under a transmitted light microscope

Rock samples are processed to produce rock slabs for textural work or thin sections and polished thin sections for petrographic or geochemical investigations. Rocks can also be crushed into small chips or powdered in preparation for different geochemical techniques.

Section of Kauri

Wood samples (primarily kauri) are trimmed and polished for microscope analysis in the Tree Ring Laboratory for the reconstruction of historic climate variations.

ESP Lab Products

  • Powders: We produce rock powders for XRF and XRD analysis. Each technique requires 2g of clay sized particles but it is best to prepare 4g.
  • Chips/grains: Rocks can be crushed into small fragments for different applications. This is the first step in single crystal chemistry followed by hand picking or separation through magnetic properties or heavy liquids. 
  • Rock Slabs: Polished rock slabs are used for macroscopic description of hand specimens as they clearly show the rock texture and textural relationships.
  • Thin sections: Thin sections are the base for petrographic work.  Standard thin section is used for petrographic analysis using transmitted light microscopes. Polished thin sections are used for petrographic analysis with reflected light microscopy and are also used for a whole raft of analytical surface techniques like electron microprobe and cathodo-luminescence.

Rock Splitting and Crushing Equipment

  • Rocklabs rock splitter/crusher: Uses two tungsten carbide wedges driven by a hydraulic press with high capacityfor breaking downrock into smaller pieces for ease of handling. Also has two tungsten plates breaking down small samples into rock chips.
  • Boyd Crusher: This crusher uses two tungsten plates to crush rock fragments, the clearance between the plates can be adjusted to control the maximum size of the rock chips produced.
  • Rocklabs Ring Mill: The ring mill is used to pulverize rock into powders for instrumental analysis, such as XRF and XRD, or wet chemistry. Uses a tungsten head.
Boyd Crusher Boyd Crusher
Rocklabs Rock Splitter/Crusher
Rock powder produced in a ring mill
Rock chips

Rock Cutting and Trimming Equipment

  • Covington Slab Saw: The slab saw is used for cutting down large rock samples into slabs for textural analysis. It uses mineral oil as a coolant and can affect possible geochemical work.
  • Metkon Geocut Saw:  The Geocut is also used for cutting down rock samples into slabs for textural analysis though accommodates smaller samples. It uses water as a coolant.
Covington Slab Saw
Metkon Geocut trimming saw
Trimmed rock samples

Grinding/ Lapping/ Polishing

  • Thin section machine: This machine consists of a trimming saw and a grinding machine. The trimming saw cuts the billet glued to the glass to a thickness of about 2mm, then grinding takes the thin section down to the required thickness for polishing.
  • Kemet 15 Lapping Machine: This machine is used to finish the grinding process (down to 800 grit), producing smooth and flat surfaces in preparation for the polishing process
  • Buehler Beta Grinder-Polisher: This machine uses a brass embedded diamond plate for flat grinding or a set of magnetic backed textile discs for polishing with polishing paste down to 1 micron.
  • Kent 3 Polishers: These polishing machines are used for finishing products for reflective light petrography or surface analytical techniques. This is the last stage in the production of polished thin sections or mounts. The lab has 3 machines for a line production system.
Buehler Beta Grinder/Polisher
Lapping machine
Kent polishers


  • Bonding jig: The bonding jig is used to hold the billet down while the epoxy sets.
  • Hot press: The hot press is operated hydraulically for extruding mounts made of bakelite or resin.
  • Mounting cups: These cups are used together with epoxy resin for extruding mounts or pucks for mounting samples.

Key Contacts