As Asian and Western countries make giant strides in mobile technology, there are a number of African techpreneurs who feel the continent has the potential to make its own original devices. Given the dominance of imported gadgets, the challenges for home-grown devices are real yet innovators still have hope.

Let us ponder this scenario: Apple is a big brand in America, while Samsung and Huawei are highly recognised in their respective continents. In Africa, we are yet to stand tall with devices engineered here for now. But one notable observation is that Africa is a main source of some rare precious minerals that are important in the manufacture of the devices.

The Democratic Republic of Congo alone supplies almost 70 per cent of the world’s tantalum metal which is an ingredient in all phones. The country has substantial reserves of columbite-tantalite or coltan, cassiterite, wolframite and gold. Coltan is the ore from which tantalum is extracted, while cassiterite produces tin.

Tantalum is a vital metal in the manufacture of compact and high performance capacitors found in electronic gadgets like mobile phones, laptops, tablets and gaming consoles.

Wolframite is the metal ore for tungsten used in vibration circuits of mobile phones.

Tin is a major ingredient in solder which is commonly used on electronic circuit boards. Gold is also present in some electronic products.

It is in the DRC that we find one of the up-coming techpreneur with ambitions of putting African home-grown devices on the tech-map. Verone Mankou, a Congolese entrepreneur has smartphones and tablets engineered in Congo. His tech-startup, VMK, boasts of a flagship tablet called Way-C and a smartphone called elikia.

VMK is derived from Vumbuka which is a word in Congo that captures the phrase ‘wake up’. Could it be a wake-up call for Africa to come up with home-grown mobile devices?

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Tungsten is an element. It its pure form, it is a soft light grey or whitish metal. It has a number of practical uses, both in its pure form and as an alloy. However, tungsten is typically not found in pure form; it is instead processed from minerals, usually wolframite or scheelite. Although making a completely positive identification of a mineral is difficult without professional experience, these particular minerals have many properties that anyone can examine to determine whether a specimen is likely one of them.

Instructions

1
Examine the mineral. Wolframite ranges from black or greyish black to brown, is opaque and is slightly metallic. Scheelite is more varied; it can be tan to dark brown, golden to pale yellow, brownish yellow, reddish yellow, greenish, colorless or white. Its crystals can be transparent or opaque, and they have a shiny or glassy appearance.

2
Rub the mineral against a streak plate, a piece of plain white unglazed porcelain. Wolframite leaves a reddish brown color on a streak plate. Scheelite makes a white streak, which may be difficult to see.

3
Scratch the mineral with the steel nail, which has a Mohs hardness of about 5. (The Mohs scale measures the hardness of minerals relative to one another.) Wolframite and sheelite each have a Mohs hardness of 4.5, so the nail will leave a mark on either.

4
Examine the other minerals that may have formed on your specimen. Wolframite often develops with topaz and quartz. Scheelite often develops with tremolite, tourmaline, topaz, vesuvianite, cassiterite, fluorite, diopside and apatite. In addition, wolframite and scheelite are often found together.

5
Measure the crystal's specific gravity -- its weight in comparison with its volume. This measurement can be taken in many ways, but all require special equipment or calculations for accuracy. However, this is a good way to identify minerals. The specific gravity of wolframite is 7.40 grams per cubic centimeter. The specific gravity of scheelite is 6.01 grams per cubic centimeter. If you do not have access to such equipment, heft the sample in your palm. Both minerals should feel fairly heavy for their size.

6
Place a magnet on a mineral thought to be wolframite. Wolframite contains iron, making it slightly metallic.

7
Shine a UV light on a mineral thought to be scheelite. Scheelite fluoresces bright white-blue under a UV light if it is very pure, and creamy yellow if it contains molybdenum.

8
Drip a small amount of diluted hydrochloric acid on the specimen. If it is scheelite, the acid will decompose it into a yellow powder.

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ForeverMetals.com, the leading retailer of wedding bands online, is proud to inform that they now have a complete line of white tungsten wedding rings both for men and women. Even if tungsten rings are relatively renowned and make up roughly one third of all men’s wedding rings traded in US alone, there are a few inherent issues regarding this superb metal. This metal is inclined to be a little grayer in color, which is far from silver, platinum and palladium when it comes to appearance. There are many clients who wish their rings made from tungsten carbide could have a similar color as platinum and white gold. Now with advances in technology this has been made possible. Soon to be couples are drawn to the stunning white metal appearance of platinum which white tungsten has, according to Forever Metals.

A lot of couples yearn for their engagement ring or wedding band to seem like white gold or platinum. With white tungsten, you can have the lavish appearance of platinum, at a portion of the cost. Unlike the usual way of plating, this extraordinary procedure will not wear down. White Tungsten is an ideal choice for couples seeking the traditional look of precious metals while having the durability of tungsten carbide.

Forever Metals offers one of the largest collections of tungsten carbide rings. At Forever Metals, they strive to give the best service for their customer to make their buying experience informative and hassle free. Along with offering the best products and services, Forever Metals also provides the affordable prices.

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Until the 1990s, titanium and tungsten were not on the market for general consumers, but since then have gained in popularity. When shopping for wedding bands today, there are many choices including various carats of white and yellow gold, platinum and silver. Titanium and tungsten are often confused since they are both hard metals, but there are many ways in which these two metals are distinct.

Hardness
Though titanium and tungsten are both very hard and durable metals, tungsten alloy is harder. The hardest form of tungsten carbide is harder than titanium alloys and can only be scratched by diamonds. Their different hardness makes a difference in engraving and resizing. Titanium can be resized and engraved, whereas tungsten is too hard for this.

Color
Tungsten carbide is usually offered in a black anodization coat only, but titanium is made in either silver/gray or black.

Durability and Allergic Properties
Many people may believe in the myth that titanium jewelry is indestructible, but though it is durable, it is by no means indestructible, and the same goes for tungsten. If a titanium wedding band should undergo extreme pressure such as being smashed in the door of a car, it could bend out of shape. A tungsten wedding band may not withstand being smashed under extreme pressure either, but instead of bending it would shatter into many pieces, which can make it a hazard.

As far as allergies to these metals, titanium is safe, but cobalt when used in tungsten carbide jewelry can cause allergic reactions in some people.

Pricing and Weight
Tungsten wedding bands are usually more expensive than titanium because of the manufacturing process. The equipment for this process is more expensive because the tungsten carbide needs to be in a vacuum or hydrogen environment that is at least 6,000 degrees Fahrenheit.

When browsing for wedding bands, keep in mind too that titanium, due to its lower density, is lighter than stainless steel, and tungsten carbide is much heavier than stainless steel.

Origins
According to Gopal S. Uphadhyaya, author of "Cemented Tungsten Carbides: Production, Properties and Testing," cemented carbides (hard metals) were introduced to the market in 1927 in Germany. The majority of the world's tungsten reserves are in China (approximately 85 percent). But there are also some smaller reserves in Korea, Russia and the state of Colorado in the United States. Almost half of the world's titanium comes from South Africa, according to the U.S Geological Survey Mineral Commodity Summaries. The other half comes mostly from Australia, Canada and the Ukraine.

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