Mananjary emerald District, Mananjary District, Vatovavy Fitovinany, Madagascari

Regional Level Types
Mananjary emerald District	District
Mananjary District	District
Vatovavy Fitovinany	Region
Madagascar	Country

An emerald mining district located 30 km SW of the town of Mananjary at the eastern coast of Madagascar. Mining started in this area around the middle of 1970s, first at Ambodibakoly. Several open pit mines were worked in the period 1983 to around 1995, and produced several thousand kgs of emerald of different sizes and quality.

The emeralds were formed cause to metasomatic processes related to the Pan-African tectonometamorphic event. 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. The most famous mine is Morafeno. One of the world's largest emerald specimens, a 536-kilogram specimen named "Heaven's Gift Emerald" was mined by the Société Orgaco of France mined the 536-kilogram in 2007.

The mines and emerald deposits can be found in two main areas, roughly divided by the main road RN25. Along RN25 there are two important market villages, Kianjovato and Irondo. In the beginning of the mining period specimens of emerald were brought to the markets and sold to gem dealers at these easily accessible villages. Thus emerald specimens from this area has been labelled as coming from Kianjovato or Irondro.

The emerald mines in the northern area (called "North zone" by Cheilletz, A. et al. 2001) is are mainly located in the Ambalahosy Nord Commune, north of Ikanjovato village (and the Ikanjovato Commune) and the RN25 road, between the Mananjary river and Vohipaky mountain. For more specific information on the different mines, please see the localities listed under the Ambalahosy Commune.

The emerald mines in the southern area (called "South zone" by Cheilletz, A. et al. 2001) is are mainly located in the Andonabe Commune, south of Irondo and the RN25 road, south and east of the Analatsitevena mountain. For more specific information on the different mines, please see the localities listed under the Andonabe Commune.

Emeralds colored by vanadium instead of chromium.

Geochronology

Mineralization age: Cambrian : 490 ± 8 Ma

Important note: This table is based only on rock and mineral ages recorded on mindat.org for this locality and is not necessarily a complete representation of the geochronology, but does give an indication of possible mineralization events relevant to this locality. As more age information is added this table may expand in the future. A break in the table simply indicates a lack of data entered here, not necessarily a break in the geologic sequence. Grey background entries are from different, related, localities.

Geologic Time				Rocks, Minerals and Events
Phanerozoic
	Paleozoic
		Cambrian
			Furongian	ⓘ Phlogopite 490 ± 8 Ma

References