h) X-Ray Diffraction (XRD) of solids filtered from the water lake in Halema’uma’u Crater, Kīlauea Volcano, Hawaii

Samples of the crater lake water were filtered in the field with a 0.45 micron filter. Subsequently, additional precipitates formed in the solute-rich samples (secondary precipitates) which were subsequently filtered in the lab with a 0.45 micron filter. The mineralogy of secondary precipitates for samples HM19-01 and HM20-01A,B,C that were collected on 10/26/2019 and on 1/17/2020, respectively was determined by X-ray diffraction (XRD). Analysis was carried out at the British Natural History Museum with a Enraf-Nonius PDS120 diffractometer equipped with a primary Germanium (111) monochromator and an INEL 120° curved position sensitive detector (PSD). Data were collected from 7-120° 2θ using Co Kalpha1 radiation with operating conditions [...]