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Sapphire Situation: Expedition to Ethiopia's sapphire fields

At the 2017 Tucson Gem Show, author Andrew Lucas was approached by Ethiopian dealers attending a seminar given by Shane McClure, Global Director, Colored Stone Svc. They proposed to Lucas and McClure to conduct research on Ethiopian gemstone deposits for GIA.

This led to correspondence between Lucas and Teweld Abay, director of the Mineral Marketing and Value Chain Directorate over the next several months to coordinate a joint project between GIA and the Ethiopian Ministry of Mines Petroleum & Natural Gas.

Tucson 2017 and 2018 were abuzz with interest regarding Ethiopian emeralds and to a lesser degree Ethiopian sapphires. A few Ethiopian dealers showed sapphires at the show that were obviously magmatic in nature. Most of the gemstones were very dark blue and heavily included with silk. There were some bright blue stones, however, that sparked a great deal of interest. News of the sapphires had begun entering the gem trade in early 2017.

As much of the talk in the gem trade was of this upcoming source of gemstones, GIA was compelled to conduct firsthand on-the-ground research. The Ethiopian Ministry of Mines also wanted third-party expertise to be involved in joint research on the Ethiopian gem deposits.

The decision was made for GIA to visit the main gem producing areas of the East African country of Ethiopia, including sapphire, emerald and opal mining areas. The expedition dates were set for the end of February 2018 through the third week of March and the first mining areas to be visited during the visit were the sapphire fields.

Ethiopia

Ethiopia is composed of over one million square miles with elevations that range from 125 m below sea level to 4,550 m with a mean elevation of 1,330 m. The terrain is dominated by high plateaus, which are divided by the Great Rift Valley.

The population of over 105 million makes it the second most populous in Africa. Ethnically, Ethiopia is composed of several ethnic groups with the two largest being Oromo (34.4%) and Amhara (27%). While the official National language is Amharic, local states will also designate working languages such as Oromo for the State of Oromia, Somali for the Sate of Sumale, and Tigrinya for the State of Tigray.

Approximately 80 per cent of the population lives in rural areas and this reflects that about 72 per cent of the workforce is involved in the agricultural industry.

Approximately 43 per cent of the population is Ethiopian Orthodox Christian, 33 per cent Muslim, and 18 per cent Protestant. Many of the tourist attractions in the country are to do with religious sites such as the Rock-Hewn Churches at Lalibela, which is a UNESCO World Heritage site. This site consists of 11 medieval monolithic cave churches from the 12th to 13th centuries and are still a place of pilgrimage and worship today.

Many of the miners were families working in small groups with women doing much of the heavy labour
Many of the miners were families working in small groups with women doing much of the heavy labour
Picks, shovels, buckets and human muscle were the only mining techniques used in the sapphire fields
Picks, shovels, buckets and human muscle were the only mining techniques used in the sapphire fields

Sapphire fields near Chila

Our expedition started with the sapphire fields near Chila. This was an area where we had the least information as to what was going on and did not know what to expect as far as the size of the mining area, the amount of miners involved or the nature of the mining. While much of what we witnessed met our preconceived ideas of the artisanal mining operations, seeing the exact nature of the mining proved very interesting, as well as learning about the reported transformation of the socio-economic nature of the area.

Geology

Based on analytical results, it is clear that the sapphires are related to alkali-basalt flows. According to geological maps, there are several alkali basalt outcrops in the area, but the maps don’t indicate their presence around Chila. However, there are clearly basalt flows near the sapphire mines. Basalt flows can cover incredibly large areas with thick layers of molten rock, often in successive events.

Based on our observations, the sapphire-containing basalt flows were deposited on a flattened basement. This basement contains heterogeneous rocks of a granitic composition that belong to the Precambrian era (older than 540 Ma). The basalt flows are much younger and were deposited in the Cenozoic period (younger than 65 Ma). The basalts erode much easier than the basement, creating a very wide valley flanked by flat plateaus.

In the centre of the valley, we could see exposed basement. The sapphires have been released from their basalt host rock by weathering. The richest sapphire concentrations are found in the centre of the valley near the riverbed, although many miners are also working on the hill flanks. According to the locals, sapphires have also been found on top of the basalt plateaus, indicating that a lot of the basalts are sapphire bearing.

Rough Ethiopian sapphires. Image courtesy Wim Vertriest/GIA
Rough Ethiopian sapphires. Image courtesy Wim Vertriest/GIA
Rough Ethiopian sapphires. Image courtesy Wim Vertriest/GIA
Rough Ethiopian sapphires. Image courtesy Wim Vertriest/GIA

Mining

All of the mining we saw was classic artisanal mining on the secondary deposits. The deposits are ideal for artisanal mining techniques and family/community mining efforts. We saw no mechanisation in the mining whatsoever. All the miners in the area first dug pits with picks and shovels. Then, the gravel was taken out of the pits, often by just flinging it to the top of the pit with a shovel or by using buckets. It was then sorted through for sapphires by hand, often with just dry picking.

It appeared that the dry sorting missed many of the smaller size sapphires and that most of the stones the artisanal miners were recovering were above one gram. This was also evident when we tried to buy samples for research in one-carat to half-gram sizes. It was difficult to find any sapphires in that range with most of the miners and traders offering one gram and larger sizes. There are potentially numerous rough sapphires under one-gram sizes being left behind in the gravels sorted by the artisanal miners.

When the miners hit ground water in the pits, they would bring it up by bucket for a very rudimentary use of water during the sorting process, which in either case was done right at the top of the pit by the small group working that pit. We did not see communal sorting or washing efforts.

The mining efforts were very labour intensive. We saw approximately as many women miners as men and the women were often performing the same heavy labour tasks such as digging with picks and shovels. The mining was always a team effort at each pit with some members digging while others went through the gravel for sapphires. The teams were almost always less than 10 people and appeared to often be family and extended family groups.

The pits themselves were often very shallow although the depths varied depending on their location. The pits that were at the bottom of the Granite Gorge were the shallowest as the weathered granite bedrock was reached after just digging to between half a metre and one and a half metres. Many of these shallow pits were being mined.

Others were abandoned after the bedrock had been reached and the potential gem-bearing gravel processed. As the mining moved away from the valley centre, up the hill flanks, the depth of the pits would often increase as bedrock was not reached until six metres in some cases. These were the deepest pits we saw. They are often approaching agricultural land or in some cases agricultural land is dug up to search for sapphires.

The deeper pits often had a problem of hitting ground water and filling up partially or completely overnight. Even some of the shallow pits had this problem if they were right at the riverbed. The miners would then have to remove the ground water first thing in the morning before mining could continue.

They usually accomplished this by hand held buckets with a miner standing in the water and shopping it up, then handing the bucket to a miner at the top of the pit who would toss it aside. If the pits were on the deeper range, there would be two miners in the pit to hand it up to the miner on the top of the pit. They may also have to continually remove water during the entire day to keep mining.

We only saw two diesel pumps being used to remove the water as the cost for the pump and fuel was likely prohibitive for most of the artisanal miners. At one crowded mining location, we saw an ingenious foot pedal powered pump to remove the water. Camels were commonly used as beasts of burden to haul material, while cows were commonly seen wandering through the mining areas.

Most of the sapphires were recovered from gravels by dry hand picking. Image courtesy Andrew Lucas/ GIA
Most of the sapphires were recovered from gravels by dry hand picking. Image courtesy Andrew Lucas/ GIA
There were many brokers in the mining areas buying stones. Image courtesy Andrew Lucas/ GIA
There were many brokers in the mining areas buying stones. Image courtesy Andrew Lucas/ GIA

Business and social aspects

The Government issues six-month licences for exploration. After the exploration licence, the parties can apply for a mining licence with the Ministry of Mines by showing them the results from the exploration, which includes the amount of material recovered. If the Government approves, the parties are issued the mineral rights for the property.

The mining along the gorge by artisanal miners is considered legal, however, the mining that moves up the hills, and is on agricultural land, is not legal at this time. Even with permission from the landowner, the mining operations are not lawful because the landowners do not own the mineral rights for their land.

The landowners usually make an arrangement with the miners that the proceeds from any sapphires found while mining on their property would be divided, usually 50/50. Many farmers are also getting involved in sapphire mining, especially the younger generation helping their family’s farming business.

We saw no foreign buyers in the sapphire fields or in the local trading town Chila. Foreign buyers are not allowed in the sapphire bearing area. In fact, it is difficult for any foreigner to come to the area. When travelling to the mining sites, we saw soldiers monitoring who was accessing the sapphire mining areas.

Since we were with the Ministry of Mines, we had permission. We were provided an official letter allowing us into the area and into the mining sites, while being accompanied by someone from the ministry.

Foreign buyers are not allowed to buy directly from artisanal miners, even in the trading town of Chila or in the nearby larger city of Aksum. Foreigners must buy from licensed brokers in Addis Ababa that have a permit to export. Most of the foreign buyers for sapphire in Ethiopia are Sri Lankans and Thais.

Gemmology

A preliminary study of the Tigray sapphires by GIA provides some technical information. Chemical analysis has shown that all sapphires have high Fe-content and no detectable Be or Cr concentrations. The high Fe-content, certain inclusions and a typical UV-VIS-NIR spectrum show that the sapphires are related to alkali basalt extrusions. This type of deposit commonly produces blue, green and yellow sapphires, all of which are found in Ethiopia.

Blue stones are dominant, with yellow and green stones being much rarer, although green zones are common in the larger stones. Parti-coloured stones are also seen.

Some dealers have also reported purple sapphires, which might be an indication that some corundum contains traces of Cr (red colour) in combination with Fe-Ti pairs (blue colour).

Most stones exhibit strong blue-green dichroism, but a considerable number have a milky appearance, which scatters the light and gives a yellow cast to the stone when illuminated from the side. These stones generally have a lighter body colour and are considered more attractive for buyers.

Summary

When the sapphire mining started, it was estimated that 4,000 people became involved very quickly and today over 10,000 people are involved in artisanal sapphire mining. Within a year, the sapphire trade made a huge impact on Chila, the local trading town.

Before the sapphire mining rush started, there was one bank office, but at the time of our visit, three banks had a branch there and the police station had expanded. We could also see many construction sites all over town. When we visited, more than 20 Ethiopian gem dealers had an office in Chila.

The deposits are potentially large. Qualities can vary depending on the exact mining location. There are three major areas being worked on, with one producing high quality bright blue stones that are smaller than the other areas that produce larger but often darker material. The average size of the sapphire rough is reported to be 3 to 7 grams. However, some of the larger stones we saw had good colour and quality, and sizes ranged from 10 to 20 grams. Other colours produced include yellow and green, but the most are blue.

With the size of the deposits and variety of qualities, mining is economically viable for the local artisanal miners. Demand from Sri Lankan and Thai buyers seems to remain strong and prices offered by miners and dealers firm. The sapphire deposits have definitely transformed the economic nature of the local communities and the town of Chila, that can be observed with the small town going from one bank to new ones opening up constantly.

The Ethiopian Government looks to work with the country’s gem trade to achieve the greatest potential from their sapphire deposits, as well as other gem deposits in their country. They are looking to brand Ethiopian gemstones and hoping to bring in investment and training to better exploit their deposits and bring new skills so the people of the country can move up the value chain into manufacturing in the future.

Ethiopia’s government and industry want to tell the story of their gemstones themselves to the global industry. For this purpose they are working with international organisations for research and training. This up and coming gemstone producer is proud of their gem wealth and looking to capitalise on it for the future of the country.

Ethiopia
Ethiopia's sapphire fields
Taken from drone footage this shot clearly shows the numerous pits seen in the mining areas. Image courtesy Wim Vertriest/GIA
Taken from drone footage this shot clearly shows the numerous pits seen in the mining areas. Image courtesy Wim Vertriest/GIA


About the authors

Andrew Lucas is Manager of Field Gemology for GIA in Carlsbad. Wim Vertriest is Supervisor Field Gemology for GIA in Bangkok, Thailand. Daniel Girma is an analytics Technician for GIA in New York. Teweldbrhan Abay is a director for the Mineral Marketing and Value Chain Directorate within the Ethiopian Ministry of Mines Petroleum and Natural Gas in Addis Ababa. Biniyam Bekele is a geologist for the Ethiopian Ministry of Mines Petroleum and Natural Gas in Addis Ababa.

This article was first published in Summer 2018 edition of InColor magazine: incolormagazine.com

Reprinted with permission from International Colored Gemstones Association: gemstone.org



















Thursday, 13 December, 2018 07:52pm
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