Sample preparation

We use polished 30 mm resin pucks for SEM and QEMSCAN analysis, made from rock, sand or drill cuttings.

The material is set in Struers low-viscosity EpoFix resin under high pressure. This forces the resin into the pore-space, enabling proper detection of pores. 

After curing, the pucks are cut or ground to expose a suitable material surface and polished to a micron smooth surface. Carbon coating is applied before QEMSCAN analysis.

30 mm polished resin puck of a sandstone block.

30 mm polished resin puck of a sandstone block.

 

Whole rock

Sandstone core plug

Core and outcrop rock samples are cut to size to fit in the puck mould. Resin is applied to the sample and subjected to high pressure to fill the pore space.

Once the resin has cured, the puck is cut to reveal a suitable interior surface. Note, please specify if you need the sample to be mounted in particular orientation.

Rocktype requires a minimum 10g of whole rock.

Drill cuttings

Dry cuttings

Wet cuttings are washed and dried before further preparation. Cuttings can be sieved to a certain particle size. The selected cuttings are then set in resin, ground and polished.

Sandstone cuttings can also be hand-picked under a stereo microscope to increase the sandstone abundance in the QEMSCAN data. 

Rocktype requires 10g of dry and 20g of wet cuttings.

We do all sample preparation in-house to ensure high quality and fast turn-around.
— Dr Henrik Omma

Heavy mineral separation

We can make heavy mineral separates from sand or solid rock.

Rocks are dis-aggregated to sand in a jaw crusher. Sand is sieved to the appropriate size fraction. Mixed sand is separated into light and heavy fractions using LST fastfloat heavy liquid with a density of 2.89 g/cc. The HM separates are cleaned and dried, ready for embedding in resin.

Rocktype requires 1g of heavy mineral separates for scanning. If you are sending us bulk rock, sand or cuttings for heavy mineral separation, we may need 100g or more to get enough separates to scan.

Vial of heavy mineral separates

Sending us samples

Please send samples to:

Rocktype
87 Divinity Road
Oxford
OX4 1LN
United Kingdom

Note: To protect the QEMSCAN x-ray detectors we only scan resin pucks prepared with Struers Epofix resin. We cannot accept thin sections or other mounts prepared with different resin.

Minimum sample quantity
Whole rock (core or outcrop) 10g
Dry cuttings 10g
Wet cuttings 20g
Sand 5g
Heavy mineral separates 1g

Sample preparation services

Sample collection
Core store sample collection - Rocktype sample collection at the British Geological Survey. Includes day rate for one person, travel expense to BGS Keyworth, core store hire and return of samples and public data to BGS.
BGS sample charge - BGS standard rate per sample of £10, rebilled at cost.
Sample preparation
Polished resin puck - Bulk sample photography, resin puck preparation, surface polishing and carbon coating. Includes cutting of bulk rock; washing, drying and sieving of cuttings as needed.
Cuttings handpicking - Manual selection of cuttings of specified lithotypes before resin puck preparation.
Heavy mineral separation - Concentration of heavy mineral grains for QEMSCAN analysis. Includes rock crushing and LST (heavy liquid) separation.
Single grain picking - Manual selection and mounting on double sided tape of 200 grains, such as zircon, garnet or rutile.

Note: We do not offer small-batch sample preparation as a separate service from our QEMSCAN analysis. We can however prepare batches of 20 or more polished resin pucks.