The town was founded in 1905 by the German colonial power and celebrated its 100th year of existence in 2005.
Tsumeb is notable for the huge mineralized pipe that lead to its foundation. The origin of the pipe has been hotly debated. The pipe penetrates more or less vertically through the Precambrian Otavi dolomite for at least 1300 m. One possibility is that the pipe was actually a gigantic ancient cave system and that the rock filling it is sand that seeped in from above. If the pipe is volcanic, as some have suggested, then the rock filling it (the "pseudo-aplite") is peculiar in the extreme. The pipe was mined in prehistoric times but those ancient workers barely scratched the surface. Most of the ore was removed in the 20th century by cut-and-fill methods. The ore was polymetallic and from it copper, lead, silver, gold, arsenic and germanium were won. There was also a fair amount of zinc present but the recovery of this metal was always difficult for technical reasons. The pipe was famous for its richness. Many millions of tonnes of ore of spectacular grade were removed. A good percentage of the ore (called "direct smelting ore") was so rich that it was sent straight to the smelter situated near the town without first having to be processed through the mineral enrichment plant. The Tsumeb mine is also renowned amongst mineral collectors. The mine produced between 1905 and to 1996 about 30 million t ore yielding 1.7 Mt copper, 2.8 Mt lead 0.9 Mt zink, as well as 80 t germanium. The average ore grade was 10% Pb, 4.3% Cu, 3.5% Zn, 100 ppm Ag, 50 ppm Ge.
It is noted for 243 valid minerals and is the type location for 56 mineral species. Some of the germanium minerals are only found in this mine.
Tsumeb, since its founding, has been primarily a mining town. The mine was originally owned by the OMEG (Otavi Minen- und Eisenbahn-Gesellschaft) and later by TCL (Tsumeb Corporation Limited) before its closure a few years ago, when the ore at depth ran out. The main shafts became flooded by ground water over a kilometre deep and the water was harvested and pumped to the capital Windhoek. (Most of Namibia is desert country). The mine has since been opened up again by a group of local entrepreneurs ("Ongopolo Mining"). A fair amount of oxidized ore remains to be recovered in the old upper levels of the mine. Whether the deepest levels will ever again ring to the sound of the miner's pick seems highly doubtful.
The other notable feature of the town is the metal smelter, also owned by Ongopolo.
Near to the town are two large and famous sinkhole lakes, Lake Otjikoto and Lake Guinas ("Gwee-nus"). Guinas, at about 500 m in diameter, is somewhat larger in area than Otjikoto. A pioneering documentary movie about scuba diving in these lakes was made by Graham Ferreira in the early 1970s. The depths of the lakes are unknown, because towards the bottom both lakes disappear into lateral cave systems, so it is not possible to use a weight to sound them. Otjikoto, which has poor visibility (owing to pollution from agricultural fertilizers used nearby), is at least 60 m deep. The water in Guinas is as clear as gin and is well over 100 m deep. Divers who have performed bounce-dives in Guinas to 80 m (strictly speaking, beyond the safe depth for SCUBA dives, especially given the altitude of the lake above sealevel) have reported that there was nothing but powdery-blue water below them. Guinas has been in existence for so long that a unique species of fish, Tilapia guinasana, has evolved in its waters.
When South Africa invaded Namibia (then German Southwest Africa) in 1914, the retreating German forces eventually threw all of their weaponry and supplies into the deep waters of Otjikoto. Some of the material has been recovered for display in museums.
One of the largest and deepest underground lakes in the world lies a little to the east of Tsumeb, on a farm called Harasib. To reach the water in the cave one has either to abseil or to descend an ancient, hand-forged ladder that hangs free of the vertical dolomite walls of the cave for over 50 m. Here, too, SCUBA divers have descended as deep as they have dared (80 m) in the crystal-clear waters and have reported nothing but deep blue below them from one ledge of dolomite to the next until nothing further could be discerned in the indigo depths.
Tsumeb is connected to the national railway network operated by TransNamib. Tsumeb was for most of the 20th century the terminus of the line but in recent times the track has been extended a further 260 km to reach Ondangwa. There have been talks of extending the line to Oshikango and having the Government of Angola build a railroad from the north to connect the two countries together.
In 2008, a cement works was planned.
Stibioclaudetite ASSB[O.sub.3] a new mineral from Tsumeb, Namibia: Stibioclaudetite has been found at the Tsumeb mine, Namibia, in bladed crystals to 6 mm association with leiteite, ludlockite, smithsonite and quartz. Previously identified specimens of claudetite from Tsumeb may well be stibioclaudetite instead.(Report)
May 01, 2009; ABSTRACT Stibioclaudetite is a new mineral species with ideal chemistry [AsSbO.sub.3]. The mineral has monoclinic symmetry,...