Welcome to AGTA GTC's Laboratory Update for November 15, 2005

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  1. A visit to Madagascar
  2. AGTA GTC on the Web

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A visit to Madagascar

When most people go on vacation, they flee from work. Not so for the staff of the AGTA GTC, for whom work is their meditation, their muse.
     This installment is devoted to a September–October 2005 survey of two different ruby and sapphire deposits in Madagascar undertaken by the AGTA GTC's Richard Hughes. He was accompanied by AGTA member, Dana Schorr, and Vincent Pardieu of Bangkok's AIGS.

Figure 1. Map of Madagascar
Map of Madagascar, showing the island's most important corundum localities, along with the authors' route. Map © Richard W. Hughes/RWH Publishing & Books

Andranondambo
Ruby and sapphire have been known from Madagascar for over 400 years, but the modern rediscovery of these gems dates from about 1991, when fine blue sapphire was discovered in southern Madagascar at Andranondambo. This set off a rush that has continued to the present day.
     To date, the Andranondambo area remains the gold standard for Madagascar sapphire, with the finest stones said to come from Tiramene, just north of Andranondambo. At the time of Vincent Pardieu's visit in June, 2005, an Australian company (S.I.A.M.) was preparing to begin work at the Andranondambo deposit.
     Andranondambo sapphires can sometimes be of spectacular quality, in many respects resembling stones from the famous Kashmir, Burma and Sri Lankan mines. Terrific faceted stones of over 20 carats are known.

Madagascar sapphire rough

A selection of sapphire rough from various deposits in Madagascar, showing the broad range of colors produced on the Island. Photo © Richard W. Hughes/RWH Publishing & Books

Ilakaka
Prior to the discovery of sapphire in October 1998, Ilakaka was just a wide spot in the road. Today it is the center of Madagascar's sapphire universe. Currently, the greatest mining activity is taking place south of the Ilakaka–Sakaraha highway, but the sapphire-bearing region is huge, perhaps 4000 sq. km. or more. Large quantities of pink sapphire are produced, as well as blue, violet, orange (including padparadscha), yellow, colorless and fancy colors.

Ilakaka

Ilakaka today
Once a small hamlet, Ilakaka has grown into a major outpost in southern Madagascar. Photo © Richard W. Hughes/RWH Publishing & Books

    Most Ilakaka sapphires are distinguished by large numbers of small zircon inclusions. Rough material is waterworn, showing little if any traces of the original crystal shape. Most stones tend to be under one carat after cutting, but bigger stones are occasionally found. Cut gems above five carats are rare.

Ilakaka market

Dealing in the market at Ilakaka. Photo © Richard W. Hughes/RWH Publishing & Books

Andilamena
Ruby and sapphire from this area has been known for over a decade, but it was not until recently that it was extensively mined. The main mining village of Moramanga is located a long day's walk from the town of Andilamena. Demand in Thailand for low-grade ruby that can be improved by filling fractures with high-RI glass has driven much of the current activity at this mine.

Dana Schorr on the trail to Moramanga a tough and extremely muddy jungle walk from Andilamena. Photo © Richard W. Hughes/RWH Publishing & Books

Moramanga

The village of Moramanga, where 15,000 people claw rubies from the bush.
Photo © Richard W. Hughes/RWH Publishing & Books

    With the exception of the Ilakaka-Sakaraha area, by far the most mining activity in Madagascar is taking place in the hills surrounding Moramanga. The scene is one straight out of America's gold rush, albeit in a jungle setting. Today, some 15,000 people have carved out a toe-hold from the surrounding forest where they mine for both ruby and sapphire.
    A day's walk south of Andilamena is a small jungle encampment at Andrebabe where fine-quality sapphires are found. The author's party was the first group of gemologists to visit this locality. At the time of their visit, only a handful of people were mining, most having left for Moramanga.

Vincent Pardieu and Richard Hughes

Vincent Pardieu and Richard Hughes at the end of a long day's walk to the Andrebabe sapphire mines south of Andilamena. Photo © Richard W. Hughes/RWH Publishing & Books

Vatomandry
The finest rubies from Madagascar occur near the town of Vatomandry, east of the capital of Antananarivo. The mining areas are at Tetezampaho, Ambidotavolo and Ambodivandrika.
     The deposit was discovered in September 2000, and soon a rush of miners descended upon the area. In February 2001, the Madagascar government closed the area and at the time of his June 2005 visit, VP found most miners had left for the Andilamena area.

Ambohimandroso
This deposit, which produces pinkish ruby and pink sapphire, was discovered in late 2004. The main mining area is located at Antsahanandriana, to the east of the road between the capital at Antananarivo and Antsirabe. By January 2005, over 2000 miners swamped the deposit. Like many mining areas in Madagascar, disputes over mining rights have created turmoil and uncertainty. At the time of Vincent Pardieu's visit in June 2005, the deposit was under military lock-and-key.

The far north
Sapphire occurs in northern Madagascar near both Diego Suarez (at Ambondromifehy) and Nosy Be. In both locales, the corundum is derived from basaltic source rocks, and so tends to occur in green, yellow and inky blue colors.
     In 1995, wood-cutters in the Ankarana forest near Ambondromifehy came across fistfuls of blue stones. At first thought to be useless, when they were later identified as sapphire, the rush was on.

Diego Sapphire

A handful of sapphire from Ambondromifehy, just south of Diego Suarez in Madagascar's far north. Photo © Richard W. Hughes/RWH Publishing & Books

Other deposits
We have just scratched the surface regarding Madagascar's corundum deposits. The above is but a sampling of the more important localities. Incredibly, according to one authority we spoke with, just ten percent of Madagascar is not gem bearing. The future looks very bright, indeed.

References and further reading

  • Kiefert, L., Schmetzer, K. et al. (1996) Sapphires from Andranondambo area, Madagascar. Journal of Gemmology, Vol. 25, No. 3, pp. 185–209.
  • Lacroix, A., 1922, 1923. Minéralogie de Madagascar. Société D’Editions Géographiques, Maritimes et Coloniales, Paris, I, 624 pp.; II, 694 pp.; III, 450 pp.
  • Milisenda, C. and Henn, U. (1996) Compositional characteristics of sapphire from a new find in Madagascar. Journal of Gemmology, Vol. 25, No. 3, pp. 177–184.
  • Milisenda, C., Henn, U. et al. (2001) New gemstone occurrences in the south-west of Madagascar. Journal of Gemmology, Vol. 27, No. 7, pp. 385–394.
  • Pezzotta, F. (2001) Madagascar: A Mineral and Gemstone Paradise. extraLapis English, No. 1, 97 pp.
  • Schwarz, D., Kanis, J. et al. (2000) Sapphires from Antsiranana province, northern Madagascar. Gems & Gemology, Vol. 36, No. 3, pp. 216–233.
  • Schwarz, D. and Schmetzer, K. (2001) Rubies from the Vatomandry area, eastern Madagascar. Journal of Gemmology, Vol. 27, No. 7, pp. 409–416.

Acknowledgments
The authors would like to thank all those who assisted in their journey, most of whom prefer to remain anonymous. We know who you are. Merci beaucoup!

dingbat

AGTA GTC on the Web
A number of clients have asked us to consider making our gemological bulletins available to a wider audience. Towards that aim, over the past few months we have built a website specifically for the AGTA Gemological Testing Center. It is now live and offers a complete archive of our e-mail bulletins, along with a full description of the lab and its services.
     See it at www.agta-gtc.org or link from AGTA’s regular site, www.agta.org.

The new AGTA-GTC website offers the most up-to-the-minute gemological news, along with a full description of the lab and its services.

dingbat
The AGTA Gemological Testing Center provides the industry and the public with a complete range of lab services, including gemstone identification, origin determination and pearl identification. Located in New York City, the laboratory is equipped with the latest, technologically advanced, investigative equipment. The AGTA GTC is committed to providing excellent service, superior value and outstanding quality. A complete list of services and detailed pricing information is available on our website, www.agta-gtc.org. Please contact us with any questions.


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