Nephrite Jade From Val Malenco, Italy: Review and Update

Alpe Mastabia, in the Val Malenco district of northern Italy, has been a source of nephrite jade since the early 2000s.Twenty-one samples from this locality were investigated by classical gemological methods; X-ray powder diffraction, combined with quantitative phase analysis; scanning electron microscopy in combination with energy-dispersive spectrometry; electron microprobe analysis; mass spectrometry; and mid-infrared spectroscopy.From a mineralogical standpoint, this jade consists mainly of tremolite amphibole, with variable amounts of other constituents, especially calcite (up to approximately 30 wt.%), but also pyroxene, apatite, and sulfide minerals.Its pale green color is related to the low iron content of the tremolite amphibole, whereas the other minerals are responsible for different colors (calcite for white, molybdenite and galena for gray).On the basis of minor and trace-element composition, we can classify this jade as dolomite-related nephrite (para-nephrite).Although new material could be recovered from this area, future production will probably be limited by access difficulties.N ephrite jade is an almost monomineralic rock, composed primarily of tremolite [Ca Mg Si O (OH) ] to actinolite 2 5 8 22 2 [Ca (Mg,Fe) Si O (OH) ] amphiboles (Leake et al., 2 5 8 22 2 1997).Although tremolite-actinolite is considered the predominant phase in nephrite jade, its specific weight percentage range is still debatable.Major sources include the Kunlun Mountains in Qinghai Province and the Xinjiang Uygur Autonomous Region of China; the East Sayan Mountains of Siberia; Chuncheon in South Korea; South Westland in the South Island of New Zealand; and Cowell, Australia (Harlow and Sorensen, 2005; Liu et al., 2011a,b;Zhang et al., 2011).A new deposit of gem-quality nephrite jade (figure 1) was discovered at the beginning of the 2000s at Alpe Mastabia, located in the Val Malenco district in the Sondrio province of northern Italy (figure 2).Mr. Pietro Nana first noticed an attractive green stone in the discarded waste materials of an abandoned talc mine (figure 3) located at an altitude of 2,077 meters (Nichol and Geiss, 2005).The events leading to the See end of article for About the