Gem-quality serpentine from Val Malenco, central Alps, Italy

Pizzo Tremogge in Val Malenco, Italy, is a source of gem-quality serpentine. Samples from this mountain locality were investigated by standard gemological and petrological methods, Raman spectroscopy, and electron microprobe analysis. The rough and polished specimens were massive aggregates, with a green to yellow color and white, gray, and black veins or spots. From a mineralogical standpoint, this material consists of all three phases of serpentine-group minerals (lizardite, antigorite, and chrysotile) alternating with other minerals such as carbonate (calcite and dolomite), quartz, chlorite, and brucite. The quantity of carved and polished material to date is small, but the latest geological prospecting indicates the outcrop's strong potential.