High-purity quartz mineralisation in kyanite quartzites, Norway

This study presents an evaluation of Norwegian kyanite quartzites from Gullsteinberget, Knosberget, Kjeksberget, Sormbrua, Tverradalen, Juovvacorru and Nasafjellet as potential deposits of high-purity quartz (HPQ) for use as raw material for special applications in high-technology industries. Fine-grained quartz, which forms 70 to 85 vol.% of these rocks, generally contains less than 50 mu g g(-1) (total sum) of the structurally incorporated trace elements B, Li, Al, Ge, Ti, Fe, Mn, K and P. The concentrations are in the same range as those found in HPQ products, which are being mined and produced in Norway and elsewhere. Quartz analyses were performed using laser ablation-inductively coupled plasma mass spectrometry. Complimentary whole-rock analyses and cathodoluminescence studies of quartz were carried out to reveal processes, which have led to the low trace-element concentrations in quartz. This discovery, together with a better knowledge of the processes leading to the formation of HPQ in kyanite quartzites, could lead to the recognition of a new global type of HPQ resource applicable for industrial use. However, the processing technology necessary to separate HPQ from kyanite quartzite economically has not been developed so far.