Manganese

Manganese is a chemical element, which is classified as a transition metal, and is commonly known by the symbol Mn. It is usually found with iron, carbon, or oxygen. Manganese is reactive and can easily combine with elements in the air and water. It is used in the production of steel, iron, and aluminum. Manganese is the 12th most abundant element in the Earth's crust, but it is never found by itself in nature. It is also a toxic trace element which means that it is needed to survive but is toxic in high concentrations.

Properties
Manganese is a gray-white metal. It is a harder than iron, but very brittle. It melts when heated to 1247 °C. Manganese is very reactive by itself. As a powder it will burn up if placed in oxygen. It decomposes in water and will dissolve in diluted acids. It is combined with steel alloys to make the steel harder and more durable. 

Occurrences
It took chemists a long time to discover the difference between iron and manganese. Both metals have very similar properties and are sometimes found together in the Earth's crust. In 1774 Johann Gottlieb Gahn, discovered the differences between both elements. One of the main ores of manganese is pyrolusite. Pyrolusite is made of the compound manganese dioxide (MnO2). Some famous chemists in Europe tried to analyze pyrolusite, but they were not successful. Gahn developed a method for removing the element from pyrolusite by heating it with carbon. The carbon sucked away the oxygen leaving only manganese.

Because manganese never occurs by itself in nature; it is always found combined with oxygen and other elements. The common ores of manganese are pyrolusite, manganite, psilomelane, and rhodochrosite. Manganese is abundant on the ocean floor in the form of nodules (large lumps of metallic ores). 

Uses
Manganese is a huge factor in the production of iron and steel. Manganese helps make inexpensive stainless steel and is also used in aluminum alloys. In steel, manganese enhanced the rolling and forging properties. Manganese also adds strength, toughness, stiffness, wear resistance, and hardness to the steel. In aluminium and antimony, manganese also makes highly ferromagnetic compounds, especially with a little copper. Manganese oxide (MnO) is used in fertilizers and ceramics, and manganese carbonate (MnCO3) is a material used in other manganese compounds. 

Health effects of manganese
Manganese is a found almost everywhere on earth. Manganese is a toxic essential trace element. This means that it is necessary for humans to live, but toxic when a high concentration is found in the human body. If you don't get enough manganese than your health will decrease, but when it is too high you will have lots of health problems. Too much manganese intake by humans comes through food, such as spinach, tea and herbs. The foods that contain the highest concentrations are grains, rice, soy beans, eggs, nuts, olive oil, green beans, and oysters. Once it has entered the body, manganese will be transported through the blood to the liver, kidneys, pancreas, and then the endocrine glands. Manganese poisoning occur mostly in the respiratory tract and brain. It can result in hallucination, and nerve damage. It can also cause Parkinson's disease, lung embolism, and bronchitis.