Groundmass Magnetic Separation

Description

Groundmass is the crypto to microcrystalline structure of a rock. It can comprise of glass, cryptocrystalline feldspar, pyroxene or olivine. Depending on the magnetic properties of the rock, the groundmass can be highly magnetic if it contains iron bearing oxides or non-magnetic if it is a felsic rock.

Procedure

1. Sieve the crushed and washed material to the target grain size.

2. Turn on the magnetic power source and set the amperage to 0.01 A.

3. Test the sample with a hand magnet.

   • If a significant amount of material sticks to the magnet. Keep the amperage at 0.01 A.

   • If a small amount of material or none stick to the magnetic, increase the amperage to 0.1 A.

Example of grain type progression during magnetic separation