Bastnäsite-(Ce) and Parisite-(Ce) From Mt. Malosa, Malawi

Bastnäsite-(Ce), which has the chemical formula (Ce,RE)(CO 3 )(F,OH), and parisite-(Ce), or Ca(Ce,RE) 2 (CO 3 ) 3 (F,OH) 2 , are cerium-dominant rare-earth (RE) carbonates.Although they very rarely form as crystals large and clean enough for faceting, one locality in Pakistan (Zagi or Zegi Mountain) has produced bastnäsite-(Ce) that has been faceted into stones up to 20 ct (Johnson, 1999;Obodda and Leavens, 2004).Gem-quality parisite-(Ce) has been reported very rarely, usually associated with Colombian emeralds such as those from Muzo (Henn et al., 1992).In fact, the mineral is named in honor of J. I. Paris, one of the first managers of the Muzo mine (Palache et al., 1963).This note reports on bastnäsite-(Ce) and parisite-(Ce) from Malawi's Mt.Malosa, where these minerals occur as well-formed crystals that locally may contain clear, gem-quality portions (e.g., figure 1).One of the authors (AG) visited the deposit in 2002 for research purposes, and has documented the geology and mineralogy of the area in other publications (e.g., Guastoni et al., 2007Guastoni et al., , 2009)). LOCATION AND ACCESSThe Zomba-Malosa massif is located in southern Malawi, ~250 km southeast of the capital city of Lilongwe (figure 2).Pegmatites containing bastnäsite-(Ce) and parisite-(Ce) are located close to the summit of Mt.Malosa (elevation ~2,000 m) and along the slopes flanking the Zomba-Malosa massif.The steep terrain makes mining dangerous and restricts accessibility in the area (figures 3 and 4).Lake Valley Minerals Ltd. (Lilongwe) is sponsoring and training local farmers in mining techniques, and assisting them with obtaining nonexclusive licenses for commercially recovering mineral specimens from this deposit.