Welcome to the MADAGASCAR mines

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MAP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

HISTORICAL NEWS

 

In 1547 Captain Jean Fonteneau said he had found a precious stone, probably from alluvial deposits. 

In 1888 the pegmatite district around Mount Bity (S of Antsirabe) was discovered by Mr. Bing. 

In 1893 Mr. Gautier reported fragments of rubellite and other tourmalines from the Betafo region pegmatite bodies. 

Mr. Vuillerme began commerce in lapidary material but not gemstones. 

The first regular shipment of gemstone began in 1904, and controls over the trade were established in 1907. 

Most of the gemstones were shipped to France and the rest to Germany and Switzerland. 

The quality of beryl tends to be much higher than that from other countries.

 

For each mine we calculated the medium value of lattice parameter.

For each mine we calculated the medium value of chemical analyses (analysed 20 point ) by EMPA (Cameca CX 827).

Mn, Se, F, Rb are under detection limits except in few cases. Li and Be are not determined

Chemical analyses have been normalized at 85%

H2O was deetermined by EA 1108 Carlo Erba ( gas cromatographer). Maharjary

 



 

 

For each mine we calculated the medium value of lattice parameter.


For each mine we calculated the medium value of chemical analyses (analysed 20 point ) by EMPA (Cameca CX 827).

Mn, Se, F, Rb are under detection limits except in few cases. Li and Be are not determined

Chemical analyses have been normalized at 85%

H2O was deetermined by EA 1108 Carlo Erba ( gas cromatographer).

INFRARED

 

Reflectance FTIR (Fourier Transform Infrared Spectra) of gemstones were acquired using a microscope IRscopeII (Bruker) accumulating 200 scans with a resolution of a cm-1 or better, in the range 7000-600 cm-1.  Here are given only the skeletal bands which lie in the interval 1500-600 cm-1 When the samples were suitably cut in direction parallel or normal to the c axis, polarized spectra were also obtained on the pinacoid or on the basis respectively or both. According to the group theory 6A2u + 16 E1u infrared modes are predicted: the E1u modes are observed in the spectrum when the electric field is perpendicular to the c-axis (ordinary ray) and the A2u modes are observed for the extraordinary ray (E|| c). Therefore, non degenerate bands (A2u) are observed on pinacoids and show intensity changes in polarization, while degenerate bands (E1u) are detected on basis spectra and show only a lowering in intensity in polarized light.

 

 

BIBLIOGRAPHY

 

1. Du Toit G. "Emeralds of Madagascar" JewelSiam Aug-Sep 1995 p. 92-95 
2. Sinkankas J. 1981 "Emeralds and Other Beryls" Pensylvania, Chilton Book Co. p.371-377