Welcome to the mines of INDIA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MAP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LOCATION

 

The known emerald mines of India are all of modern times. No evidence of ancient emerald mines has been found. It is probably that emeralds used in ancient jewelry were stones that found their way into India from ancient Egypt. In Egypt, emerald mines and working tools and other equipment dating to about 1650 BC have been found.

 

HISTORICAL INFORMATION

 

The modern history of emeralds in India began with the discovery in 1943 of green crystals near Kaliguman near the fortress of Kumalgarh in south Rajastan. The  Kaliguman mine was opened in 1944. 

About in 1945, the deposits of Bubani and Rajgarh were located. 

Also in 1945, the Tekhi deposits north of Kaliguman were found in the same rock belt. 

Emerald lore is deeply ingrained in Indian culture, and the high esteem this gem held in antiquity, and still holds, is described by Tagore in his Màni-Màni, a work largely devoted to ancient Indian gem lore. 

Emerald is mentioned in the great sanskrit epic the Mahabharata, probably compiled in its present form between the first and third century A. D. 

Later sanskrit lapidaries rank emerald fifth among the precious stone, preceded only by diamond, pearl, ruby and sapphire.

 

GEOLOGY


The emerald-bearing schists strike NE-SW over a distance of 200 km. The native rocks are a suite of Precambrina phyllites, biotite and other micas schists, sometimes containing feldspars, talc schist, vermiculite schist, associated with altered peridodites and intruded by quartz veins, granitic pegmatites, and tourmaline-bearing granitic rocks.

 

MINERALIZATION

The emerald-bearing schists strike NE-SW over a distance of 200 km. The native rocks are a suite of Precambrina phyllites, biotite and other micas schists, sometimes containing feldspars, talc schist, vermiculite schist, associated with altered peridodites and intruded by quartz veins, granitic pegmatites, and tourmaline-bearing granitic rocks.

 

 

 

 

 

 

For each mine we calculated the medium value of lattice parameter.For each mines 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%.In this sample it is impossible to calculate the lattice parametre and water value cause the analyses are destructive and the sample is worked.

INFRARED

 

Reflectance FTIR (Fourier Transform Infrared Spectra) of gemstones have been 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. Sinkankas J. 1981 "Emeralds and Other Beryls" Pensylvania, Chilton Book Co. p.371-377

 

Contents: 

 

Map

 

Location

 

History

 

Geology

 

Mineralization

 

Gemology 

 

Composition

 

Infrared

 

References