REPORT: Mineralogical, chemical and textural characterization of selected pegmatite and spodumene samples

BALDO, E.; DAHLQUIST, J.A.; COLOMBO, F.

2016-10-01

2017-03-01

Rec.Nat.No Renov.-Minerales metalicos

Spodumene from pegmatites may be variably altered by hydrothermal or meteoric processes to albite, muscovite, chlorite and clay minerals, among other phases. Since these minerals accept only minor or negligible amounts of Li in their crystal structures (with the exception of some chlorites), the net result is a loss of Li, which is mostly carried away in solution. The alteration assemblage may provide clues as to the process, thus giving tools to evaluate whether it could be restricted to near-surface levels or if it may be related to higher-temperature deuteric fluids which could have affected larger and deeper volumes of the pegmatite. To shed further light on this issue 9 samples were analyzed using a combination of studies including X-ray diffraction (XRD), scanning electron microscopy combined with electron microprobe analyses, and analyses of bulk samples (whole-rock chemistry). The samples included in this study were supplied by Dr. Gustavo Rodríguez (Dark Horse).