Yellow scapolite from Ihosy, Madagascar

Abstract

Attractive yellow to light greenish yellow gem scapolites have been mined from a skarn deposit near the town of Ihosy, in southern Madagascar, since the late 1990s. Chemical analysis indicates that the scapolites have a mostly meionite content, with lesser amounts of marialite and a small percentage of silvialite. These results are agreeable with the RI measurements and IR spectra. Inclusions were identified as diopside, garnet (andradite-grossular), and mica (probably phlogopite), consistent with the minerals accompanying scapolite in Ihosy skarns. The samples' UV fluorescence appears to be distinctive from that of commercially available scapolites from other localities. © 2010 Gemological Institute of America.