What do you know about Cs and Pollucite?

XRF

In this month’s newsletter we will talk about the rare and valuable element Caesium (Cs) which has been gaining interest in the minerals industry. Pioneer Resources recently reported a resource estimate of 10,500 tonnes of caesium ore at their Sinclair deposit in Western Australia. This deposit contains a grade of 17.1 % caesium oxide (Cs2O) in the form of pollucite.

Pollucite is a rare caesium-rich zeolite mineral (Cs,Na)2Al2Si4O12 · 2H2O) and forms in extremely differentiated zones of rare lithium-caesium-tantalum pegmatite systems. Caesium is most commonly used as a lubricant for oil and gas drilling. In addition to the Sinclair deposit, it is also found in economic concentrations at the Tanco Mine in Canada and Bikita Mine in Zimbabwe.

A combination of portable X-Ray fluorescence (pXRF; Fig. 1) and near infrared (NIR) spectroscopy can be used to detect elevated Cs and pollucite, respectively. Most pXRF units report Cs and a Cs calibration can be developed on the Bruker Titan to provide more robust results. Pollucite produces a diagnostic spectrum in the near infrared (NIR) region (Fig. 2) and can be detected using portable devices such as the TerraSpec ASD.

Figure 1 A portable XRF spectrum of a Caesium-rich sample (red). X-ray emission lines for Caesium are indicated in blue.

Figure 1 A portable XRF spectrum of a Caesium-rich sample (red). X-ray emission lines for Caesium are indicated in blue.

Figure 2 - NIR Spectrum of pollucite with a number of diagnostic absorption features, particularly at lower wavelengths (~960 and 1150nm).

Figure 2 – NIR Spectrum of pollucite with a number of diagnostic absorption features, particularly at lower wavelengths (~960 and 1150nm).

Share