GemNotes

NEW FIND: EAST AFRICAN GOLDEN TOURMALINE

At first sight you might think it’s andalusite. It has an odd orangy brown color with the hints of green often glimpsed in andalusite. In reality, it’s a golden brown elbaite tourmaline from Kenya.”It was quite rare in East Africa until recently,” says miner-geologist Campbell Bridges. But two mines opened about half a year ago, one in the Mangari area of Tsavo West National Park and another on the M’gama Ridge south of the Taita Hills in south-eastern Kenya. The new finds are part of the Mozambique belt, a geologic mobile, orogenic belt that is the source of many east African gems.

The golden tourmalines occur in the Usangaran formation of the belt. Bridges says the major mode of occurrence is in pegmatites and quartz veins within graphite and mica meta-gneisses.

The golden tourmaline enjoys all the optical and physical properties of tourmaline, including strong dichroism. Bridges says the tourmaline is probably not colored by iron as might be suspected, rather by manganese, which adds to the gem’s unusual nature.

“The time to buy is now as there are good quantities available at reasonable prices, mostly in a 1- to 2-ct. range,” advises Bridges. “Prices are likely to go up as larger jewelry producers look into the gem’s beauty and availability.” For more information, contact Bridges Exploration Ltd., P.O. Box 49192, Nairobi, Kenya; fax (254-2) 219-773.

ZAMBIAN EMERALDS: AN UPDATE

[This report is by Giovanni Bossi, an Italian geologist and graduate gemologist who currently leads a World Bank-financed program aimed at developing and increasing gemstone production in Zambia.]

Zambia, long known as a source of emeralds and other gems, is gaining increasing amounts of attention as political and economic changes ease mining restrictions and lead to better promotion of the country’s natural resources.

Gem mining got off to a rocky start when the first emerald specimens were found in the early 1930s in the Copperbelt area of the country (which was then a British colony called Northern Rhodesia). The discovery caused little sensation because copper was considered more important; in fact, almost a fourth of the world’s copper came from this area.

Emerald mining didn’t become a regular activity in Zambia until the 1970s, when Kagem Mining Co. was founded under then-President Kaunda. Kagem – owned by the government and three other partners – held a monopoly on emerald mining and marketing. The quality and quantity of emeralds mined in Zambia during this period was impressive. A National Geographic magazine article in the 1980s estimated the real (not declared) value of Zambian emerald exports at $200 million annually.

Changes: Kaunda was removed from office in 1991, and the subsequent democratization and liberalization of Zambia led to great changes in the emerald-bearing region at N’dola. In the past few years, for example, the government has made it much easier to obtain a mining license, eased restrictions on foreign investment in mines, allowed foreign companies to set up operations without a local partner holding a majority interest and dropped duty fees on imported machinery and equipment.

In conjunction with the World Bank, the government also is deciding how to make better use of subsoil resources and how to market them.

Marketing shouldn’t be a problem. Zambian emerald shows strong green color with bluish highlights. And unlike Colombia or Brazil, Zambia commonly produces very clear emerald crystals (few inclusions).

Other gems mined in Zambia include amethyst, aquamarine, diamond, garnet, morganite, tourmaline and garnet. Yellow topaz has been reported, though this writer has not seen any yet.

Some difficulties: The emerald-bearing region itself is restricted and guarded by police and army personnel. The conditions are barely rudimentary, with no telephones or electricity (though the cities of Kitwe and N’dola are not far off). The area consists of undrained marshland, with water-bearing strata always closer to the surface than emerald-bearing rock. To mine effectively, water must be pumped out constantly.

This makes mining expensive and explains why most of the approximately 200 plots aren’t being worked. The smallest investment needed for effective production over 12 months is estimated at $2 million. Few local enterprises can afford that much, so they’re looking for foreign investment.

Despite the problems, the potential for fine emerald production remains very high. The productive settlements are concentrated in the middle part of one of three mineralized belts.

The remaining area is virtually untouched except for some very narrow, dangerous pits dug out by illegal miners. In fact, unauthorized mining operations have fed a flourishing underground market for rough emeralds. These stones are absorbed mostly by central African buyers who rely on a well-organized commercial network of buyers from cutting centers such as Idar-Oberstein, Germany, and Geneva, Switzerland.

The future of Zambia’s gem mining industry appears bright. Zambia is one of the most politically stable countries in south central Africa. And with the incentives for foreign investment and the importance and riches of the subsoil, it’s not difficult to foresee Zambia becoming one of Africa’s leading countries economically.

NICOLET IMAGING ACQUIRES IRT

Nicolet Imaging Systems has acquired all business assets of IRT Corp., a San Diego company that filed for protection from creditors under Chapter 11 of the U.S. Bankruptcy Act in July.

NIS, owned by ThermoSpectra Corp., reportedly paid $7.2 million for the assets, including a gemstone processing service that treats gemstones (mostly topaz). “Now that the strengths and resources of IRT and Nicolet Imaging Systems are combined, we are equally excited about the many improvements we plan to make to further enhance our service and quality for our customers,” says Lewis A. Parks, manager of NIS’s Radiation Processing Group.

NIS enhances topaz color by heat treatment and a combination of neutron and electron radiation. Its services include “gem counting,” in which radioactive gems are measured for radioactivity before they are released to licensed receivers, says Frank Rich, operations manager.

Nicolet Imaging Systems, 7695 Formula Place, San Diego, Cal. 92121; (619) 271-6330.

CORRECTION

An article on synthetic citrine and amethyst (December JCK, page 21) referred to “cabbed or cut” material. The correct term is cobbed (hammered).