The pegmatites of Emerald Subtype. Emerald
crystals up to many centimeters long, formed inside the pegmatites at the contact with the hosting basic rocks. They also formed outside the pegmatite in a phlogopitic unit that was derived by the reaction of the basic gneiss with the fluids liberated by the pegmatitic magma during the cooling down phase. The emerald
crystals produced in the area are of superior quality for gem industry. An abundance of emeralds
, with crystals weighing up to 1 kg and a total of some 1000 kg, have been mined.
In recent literature the locality has been known as "Morafeno" or as the Mananjary region near Ambodibakoly. These deposits have also sometimes been known as the Mananjary or Ifanadiana emerald deposits.
Ref: Madagascar, extraLapis English No.1, 2001, p. 64