Metal poisoning – What are the symptoms?

Posted March 21st 2017

Although we come in to contact with various metals all the time in our day-to-day lives, many metals can be toxic to humans and metal poisoning is something that everyone should know how to identify and avoid.

Heavy metal poisoning, is when heavy metals accumulate in the soft tissues of the body. Heavy metals include aluminium, arsenic, barium, lithium, mercury, nickel, silver, tin and many more. The symptoms can vary depending on which metal is present. Below we have outlined some of the most common types of metals associated with heavy metal poisoning, and the symptoms you should look out for.


Symptoms of arsenic poisoning can include abdominal pains, nausea and vomiting and diarrhea, sometimes containing blood. For more severe cases, that develop through long time exposure you should watch out for darkening of the skin, thickening skin and numbness as well as the above. The most common cause of arsenic poisoning is contaminated drinking water, which can be caused by mining, agriculture and toxic waste sites. Unsurprisingly, the areas that are most affected by this are those with a lack of safe drinking water such as Bangladesh and West Bengal. Other countries that have high levels of naturally occurring arsenic in their groundwater include Argentina, Mexico, Chile, Taiwan and Vietnam.


Lead poisoning is a very real danger for those who work in lead production, and proper precautions should be taken at all times. Symptoms can include abdominal pain, headaches, memory problems and constipation, whilst severe cases can lead to coma and even death. In 2013, lead was attributed to 853,000 deaths and is believed to account for 0.6% of disease in the world.

The effects can vary depending on age and how often one is exposed to lead, and it occurs more commonly in underdeveloped countries. Since concerns were raised about the possible damage caused by exposure to lead in the latter half of the twentieth century, levels of lead found in blood have been declining but low-level lead exposure still occurs.


Mercury is commonly used by dentists and dental hygienists, but it can affect our lungs, brain and skin and should always be handled with care. Concerns have been raised in the past about the level of mercury contained in amalgam fillings but amalgam is still used, although there are other tooth coloured materials that are slowly becoming more popular

Mercury poisoning, can affect memory, cause trouble hearing and result in skin problems and rashes. Symptoms, as with other metals, depend on the level of exposure so you should always be cautious of this.

Metal poisoning – What are the symptoms?

The most expensive coins in the world

Posted March 15th 2017

When we think about currency, it is sometimes to surprising to realise that different coins may be made of the same, or similar, materials, and yet possess completely different values. Generally, the older and rarer a coin is, the more value it will carry, although some coins might also be considered valuable for other reasons as we explain below.

The flowing hair dollar

The flowing hair dollar is the first dollar that was ever issued by the United States government. Dating back to 1794, the coin was based on the design of the Spanish dollar and is made of an alloy that consists of mainly silver with a small amount of copper. As this coin was only in production for two years, it is understandably rare and has long been considered one of the most valuable additions to a coin collection. In 2013, one specimen was sold for $10,016,875 – the highest recorded price paid for a coin.

The double eagle

The double eagle, a coin made from 90 percent gold, is a rare sight indeed. Produced in 1933, it was a 20-dollar coin that was put into production but never released into circulation. Thanks to the Gold Reserve Act of 1934, by the time the coin was finished it was no longer considered legal tender and most of the coins were melted down. Two were given to the U.S. National Numismatic Collection and some were smuggled out, although it is thought that only 40 of the coins are still in existence. In 2002, a private owner purchased one of the coins for $7.59 million.

The Brasher Doubloon

The Brasher Doubloon is a privately minted coin that was produced by Ephraim Brasher in 1787. Both a goldsmith and a silversmith, Brasher minted the coins when he petitioned the State of New York to produce copper coins. Considered very rare, only a small number of these coins are in existence with one know to have been sold to a Wall Street firm for $7.4 million.

The Edward III Florin

The oldest coin on our list, this dates back to 1343 and was produced by King Edward III in an attempt to provide coinage suitable for use in Europe and England simultaneously. It was made of gold and at the time carried a value of six shillings. Unfortunately, the coins were considered underweight and were put out of use after only a few months with the order to melt them down in order to produce a coin called the gold noble instead. As such, there are only three copies of this coin known to exist currently. Two of them are on display in the British Museum and the last know example was sold at auction in 2006 for £460,000.

he most expensive coins in the world

The lost secret of Damascus Steel

Posted March 2nd 2017

Once popularly used in the manufacture of sword blades in the East, Damascus steel has been around for centuries. The blades it produces are distinctive looking with a mottled pattern to the metal that looks almost like pooling water. As well as their beauty however, the blades made using Damascus steel were famed for having keen edges and being extremely durable. Damascus steel is said to have been named after the city of Damascus, where such swords and blades would have been used during the 16th to 18th centuries. However, it is also possible that is takes its name from damask fabric as a comparison of the patterns between the two.

Although the original method of forging Damascus steel was lost when the material fell into disuse, modern blacksmiths have found ways of recreating it to a certain standard. Billet welding, is a popular method, and employs the technique of welding steel and iron together in layers to form a ‘billet’. This is also known as ‘pattern welding’ and the technique gives a finished product that has the same patterns as Damascus steel due to the layering of the elements. This ‘modern Damascus steel’ is often used in kitchen knives today.

Traditional cast Damascus blades would have been made from wootz, which is a type of steel originating in India. Wootz steel is thought to have been made by melting iron and steel together in a crucible. There must be plenty of carbon present as this is absorbed during the melting process. As the alloy cools slowly, the swirling patterns are formed from the carbide contents giving the unique finish the material is famous for. Although some metallurgists claim to have been able to replicate the production of wootz steel, it is unlikely it has been reproduced to the same standard as the original material. Pavel Petrovitch Anosov, a Russian metallurgist, documented four different ways to produce steel with similar patterns for example, although he passed away before being able to fully record his research and findings. Anosov was looking for a way to reproduce Bulat steel, a type of steel alloy found in Russian medieval weapons and popularly associated with Genghis Khan and the Mongols – another form of Damascus steel.