This article page is a part of the article “World Mining Report 2005” for November – December and includes estimates from both official and unofficial sources of active mining deposits in Africa.
Related Article: World Mining Report 2005 – List of Countries
Ongoing war in the Democratic Republic of Congo (DRC) has made gem production sporadic, and the precise source of the gemstones coming out is difficult to determine.
One source of fine gem tourmaline is the area around Walikale, on the eastern end of the country near the Rwandan border. After DRC troops drove Rwandan troops out of the area during a conflict in 2002, gems began to flow out. Dealers estimate that as of late 2004, approximately 20 to 30 kilograms of fine blue to green tourmaline were coming out of the country, although not necessarily all from the area around Walikale. Most of the material is green, although some is blue-green, yellow-green, or bright pink. The rough will cut into stones of up to three to five carats.
The country is also said to be a source of limited quantities of very fine red andesine, a type of feldspar, but no specifics were available on locality or production.
Known primarily for its brown opal — which occurs in nodules, sometimes with play of color — Ethiopia is now also producing white opal, crystal opal, contra luz opal, and many other variations. Production remains limited.
Kenya has long been known as a source of ruby, and a recent find near the town of Baringo in Kenya’s Rift Valley has generated some new excitement. The material is properly described as pink corundum, with much of it falling on the "pink sapphire" end of the scale, and some of it rich enough in color to be classified as ruby. A single miner has claimed a significant percentage of the area. The mine officially opened in July and is expected to produce about half a kilogram of corundum per month. The region is also being worked by a variety of independent miners, who are finding ruby sporadically — up to two kilograms a month.
The John Saul Mine, which produces the bulk of Kenya’s annual ruby exports, continues to produce steadily. There are some other major ruby mining operations in the area around Tsavo National Park, although they generally produce cabochon-grade material.
Another exciting find, discovered in late 2004, is a color-change garnet that is said to resemble fine alexandrite, going from blue or green in daylight to pink or red in incandescent light. The deposit is located near Taita Taveta, Coast province. Production is not extensive — less than a kilogram per month — but promises to be steady.
Prospects are looking up for a signature Kenyan gemstone, tsavorite garnet. At the biggest single producer, the Scorpion Mine, some new pockets have opened up that are pushing production higher than it has been at any time this decade, approximately three to four kilograms a month of mixed-grade material.
Also from the Taita Taveta area is a steady production of golden tourmaline. The color ranges from the highly sought-after bright yellow to a darker yellow-green or yellow-brown. The region tends to produce large stones, typically in the one to six carat range, and sometimes as large as 10 or 20 carats. Average production ranges from three to six kilograms per month.
Kenya also produces amethyst, iolite, aquamarine, and various species of garnet. At press time, there were rumors of a new find of aquamarine, but nothing had been confirmed.
Madagascar’s gemstone production boomed in the 1990s and has been sustained in the early years of this decade. The vast mining zone centered around the towns of Ilakaka and Sakaraha in the south central part of the country is still producing in quantity, especially pink and blue sapphire. The area is mined by a combination of artisanal miners — usually under the control of a single broker who finances the mines — and private investors. In addition to the sapphire, the area produces garnet, alexandrite, aquamarine, morganite, amethyst, and rose quartz.
The ruby deposit at Andilamena, in the northeastern part of the country, yielded a new find in March 2005. The new material is a very rich pink, sometimes edging over the boundary into pink sapphire, and without a lot of inclusions.
Vatomandry, the other major ruby deposit discovered in 2000, is still producing very small rough. Most of this material has a strong purple component that will turn red with heat treatment. The colors from this deposit are gradually improving, but it produces little rough that will cut more than a 1.5-carat stone.
In the north, fancy-color sapphire is still coming out of Diego Suarez. The area is producing more large, blue sapphire in the two- to seven-carat range than before, but tends to have a lot of green.
A pink tourmaline mine just opened near Antsirabe, and while it is not yet producing significant quantities, early reports say the color is deep rubellite pink and the rough will cut clean stones up to three carats.
Another new mine in Vangainrano is producing fine aquamarine and green beryl in sizes from three to 70 carats.
Pezzottaite, a pink beryl that has the distinction of being the newest gemstone to be recognized by the International Mineralogical Association, was discovered near Ambatovita. The initial pocket appears to be mined out, but miners are continuing to work the area and will occasionally find a stone or two.
Gemstone mining in Malawi is almost all done on an artisanal basis, used by locals as a way of supplementing their income. One exception to this is the ruby and sapphire mine at Chimwadzulu Hill in the south central part of the country.
Chimwadzulu is the single biggest mine in Malawi and is responsible for the bulk of the country’s gemstone exports. It’s being worked by a private operator, who is currently doing test mapping of the deposit and some mining, amounting to about 4.5 kilograms of facetable material annually. The deposit produces a range of sizes — generally less than two carats, but larger stones have been found. The color of the corundum goes from a light pink-orange (padparadscha) to pink to deep purple, and can be sold unheated. The material is being marketed in the United States by a single supplier as Nyala ruby.
Another active area is Mzimba, in the northern part of the country near the border with Zambia. Mzimba’s main gemstone is aquamarine, but it also produces other types of beryl, as well as garnet, amethyst, and rose quartz.
Although Mozambique undoubtedly has huge gemstone potential — it lends its name to the infamous Mozambique Belt that gave rise to the gem mines of Kenya and Tanzania — exact production figures are hard to come by.
The major gem-producing areas are in Nampula and Zambezia provinces in the north, which produce aquamarine, tourmaline, amethyst, emerald, morganite, and rose quartz. Official figures for gem production are generally less than 15 kilograms per year for gems of all types; unofficial estimates put the amount in the hundreds of kilograms per year, mostly in aquamarine and tourmaline.
Compared to its diamond output, Namibia’s colored stone production is relatively small but with some larger mechanized operations. One of the biggest current producers is Erongo, which has a major deposit of demantoid garnet. Mining is active, with limited mechanization, and the deposit produces an estimated two kilograms of gem-quality demantoid garnet per month. The Erongo region is also a source of aquamarine, topaz, and garnet.
Neu Schwaben, in the Karibib area, produced large quantities of high-quality, blue-green tourmaline in the mid-1990s. It is still thought to have vast reserves, but at last report only about 200 local miners were working the deposits, mostly surface alluvial material. Production has been small and sporadic.
Very fine quality orange spessartite garnet has been found in the Hartmann Mountains, near the Kunene River in the north. The mine is still being worked by a single owner, but produces relatively little.
Over the years, Nigeria has intermittently produced some of the world’s most impressive gemstones. In recent years, much of the activity has focused on the southern part of the country, in particular, Oyo state. Oyo was the site of the infamous rubellite tourmaline and spessartite garnet finds of the late 1990s, and the Ofiki and Saki areas are still producing pink tourmaline in a range of colors, including deep pink. A copper-bearing tourmaline that closely resembles the neon blue and green tourmalines from Brazil’s Paraíba state is still being mined in Idikko and Iganna. Olode produces some spessartite garnet, as well as aquamarine, amethyst, and tourmaline in colors ranging from pink to blue and blue-green. Although mining is active, production currently has little impact on the global market.
Also in the south, neighboring Kwara state produces a variety of tourmaline. The shades most often seen on the market are blue and green, although some sites produce yellow-green, pink, and bicolor tourmaline.
In the central part of the country, the Jos Plateau, which covers parts of Plateau, Kaduna, Bauchi, and Nasarawa states, forms a separate geological belt that has been mined for gemstones for many years.
Kaduna and Bauchi states in the north produce blue sapphire in a number of locations, which is usually found in association with zircon. Kaduna also has deposits of aquamarine, morganite, goshenite, and multiple tourmaline mines, mostly producing pink tourmaline. Bauchi, in addition to sapphire, is a significant source of amethyst and white, blue, and yellow topaz.
Nasarawa state produces pink and green tourmaline, aquamarine, emerald, green beryl, and topaz, while Plateau state has aquamarine, almandine and pyrope garnets, and white topaz.
Geological surveys have found that Somaliland is rich in a wide variety of gemstones. The western part of the country has emerald deposits as well as aquamarine. There have also been finds of ruby, sapphire, orange to yellow opal, and many different types of garnet. Mining and exploration are done on a fairly limited basis, and few of the gems mined make a significant impact on the world market.
Though one of the world’s best-known sources of diamond, South Africa produces little in the way of colored gemstones. There are known deposits of emerald and amethyst, but the only gemstone material produced in any significant quantity is tiger’s eye quartz, for which South Africa is one of the world’s major suppliers.
Tanzania is one of Africa’s most important sources of colored gemstones, employing well over half a million small-scale miners at deposits that h2 the length of the country.
The single gem that’s historically gotten the most attention is tanzanite, a blue zoisite whose only known source is the deposit at Merelani, near the city of Arusha in northern Tanzania. The deposit is broken into four blocks, labeled A through D. Block A is mostly inactive. Blocks B and D are mined by small-scale miners, and their output has been gradually declining over the years as the mines get deeper and more difficult to work. Block C is being worked by TanzaniteOne Ltd. (formerly African Gem Resources or AFGEM); the company has set up a mechanized operation that produced nearly 115 kilograms of rough in the first half of 2005.
Also in the northern part of the country, the Manyara area alexandrite and emerald deposits are producing very little at the moment, although there is some active iolite mining nearby. The ruby mines near Longido continue to produce steadily.
The Umba region, which produces ruby, sapphire, rhodolite garnet, and tourmaline, is still being actively mined, but is producing less than it has in the past, in part due to the depth of the mines and miners’ limited equipment.
Tanzania was the first place that tsavorite garnet was discovered, in an area called Lemshuko, south of Arusha. The area has both hard-rock and alluvial deposits of tsavorite that continue to produce high-quality material, and recently investors have begun setting up mechanized mining operations in the area. A few miles south of the tsavorite area there are also active rhodolite garnet mines.
Moving to the east of Lemshuko, the ruby mines at Losongonoi are more active than ever. Foreign and local investors have started doing some large-scale mining there for the first time.
In central Tanzania, Morogoro has produced some very exciting finds within the past couple of years. The ones that have gotten the most buzz are the pink and red spinels that are found near Mahenge. The Morogoro region is also host to a new deposit of moonstone, which has produced several hundred kilograms of rough so far.
In the south, near the border with Mozambique, are two of Tanzania’s biggest gem deposits, Songea and Tunduru. Songea is known primarily for its ruby and sapphire.
Tunduru produces almost everything, including ruby, sapphire, spinel, garnet, alexandrite, and chrysoberyl. These areas are also producing less than before; they are alluvial deposits, and all of the material that can be easily reached has already been recovered.
In the southeastern corner of the country, the tsavorite mines in Mtwara that made a big splash in the market several years back appear to be mined out.
Mining is the backbone of Zambia’s economy, accounting for about 80 percent of export earnings, and about a quarter of that is due to gemstone mining. The vast majority of that — about 80 percent — is emerald exports. Emerald mining is centered around the Kafubu area in the north, near the border with the Democratic Republic of Congo. While the majority of the miners there are independent, small-scale miners, the bulk of the production is mined by a few large companies with mechanized, open pits. Government estimates put annual production at anywhere from 500 to 1,000 kilograms of emerald per year.
While emerald is the country’s biggest gem export in value terms, amethyst is the biggest export by volume, accounting for an estimated 700 tons of material each year. The bulk of the production is centered in the Mapatizya area near the southern border, which has a single large, mechanized operation and a number of small-scale miners.
The Lundazi area, on the eastern border near Malawi, is best known for its aquamarine. The region is also the source of “canary” tourmaline, a bright yellow tourmaline that has found a huge market in Japan. The region produces several hundred kilograms of aquamarine per year, approximately two kilograms of the canary tourmaline, and some spessartite garnet.
The Mkushi region produces a wide variety of tourmaline, from dark pink rubellite to pink and green bicolored stones to green and dark blue. Local dealers report that new deposits are being discovered constantly.
The only major mining operation in Zimbabwe at present is the well-known Sandawana emerald mines in the Zvishavane region of southwestern Zimbabwe. The mine is being worked by a private company, which has set up a mechanized operation there. The deposit is known for producing emerald of excellent color but in very small sizes, generally cutting gems of under 4 mm in diameter. The mine produces roughly 15 to 20 kilograms of rough emerald per month.
Zimbabwe also has deposits of aquamarine, chrysoberyl, alexandrite, tourmaline, and yellow, green, and pink beryl.