9. Kaolin
Kaolin is a soft white mineral which has a large array of uses. It is most commonly found in the form of kaolin clay, a fine clay which was originally produced in China, which is why this clay is sometimes referred to as “China clay.” Among the many uses for this mineral are the paper industry, medications, skincare products, porcelain, and cosmetics. Sources of this mineral can be found all over the world, including the United States, China, Brazil, Australia, and parts of Eastern Europe.
The name comes from the Chinese “Gaoling,” a reference to a mountain which provided a source of the raw mineral. The Chinese used this mineral to produce their famously fine porcelain, and when European explorers were introduced to Chinese ceramics, many of them remarked on the delicate quality of Chinese ceramic work. This was made by possible by kaolin, a material that Europeans were not familiar with, and European ceramicists spent centuries trying to replicate the techniques used in China to produce porcelain.
Today, the secret of Chinese ceramics is out, and manufacturing companies all over the world utilize kaolin in their ceramics. In high concentrations, the mineral produces fine white pieces with a high level of tensile strength, and it can be used to produce several styles of ceramic. Kaolin clay can also be blended with other clays to create specific blends.
The mineral also has an ancient use as a skincare product. Like other clays, kaolin is very absorbent, and it can pull oils and dirt out of the skin. It is commonly used in clay masks or as an additive to baths to sooth the skin, and it is also included in numerous cosmetics. Powdered forms may be dusted on the face to absorb oil and reduce greasiness, while mineralized creams can be used to soothe dry skin or to reduce oiliness, depending on how they are formulated. Companies which carry natural skin care products often stock pure kaolin which people can use to make their own cosmetics and skin care products.
Another historic use of this mineral is as a remedy for gastrointestinal upset. People once ate kaolin because the clay coated the stomach to soothe irritation, and it absorbed bacteria and viruses which caused disease, as well as absorbing loose water, which caused the stools to firm. Some cultures continue to eat clays for stomach pain, and the mineral has also been integrated into many stomach care products, such as the liquid suspensions people take to treat diarrhea.
One of the most widespread uses of kaolin today is in paper manufacturing. The mineral is used to coat and fill paper, and the paper industry demands huge volumes of it annually. Varying levels of kaolin can be used to change the texture and appearance of paper products.
10. Iron ore
Iron ore is any rock or mineral from which iron can economically be extracted. Iron ore comes in a variety of colors, including dark gray, bright yellow, deep purple, and rusty red. The iron comes in the form of iron oxides such as magnetite, hematite, limonite, goethite, or siderite. Economically viable forms of iron ore contain between 25% and 60% iron. In the old days of mining, some ores had 66% iron and could be fed into iron-making blast furnaces directly. These were known as "natural ores."
The three primary sources of iron ore are banded iron formations, magmatic magnetite ore deposits, and hematite ore. The most iron ore is extracted from banded iron formations, geological structures laid down mostly between 3 and 1.2 billion years ago. Blue-green algae released oxygen in the days when the atmosphere and oceans were very oxygen-poor, binding together with dissolved iron in the world's oceans. These iron fixation events went through cycles as the algae had alternating blooms and busts, leaving the characteristic bands seen in banded iron formations. The iron ore is in either the form of magnetite or hematite. Banded iron formations are found on all continents, but especially rich deposits are found in Australia, Brazil, and the United States.
Another prominent source of iron ore is found as magmatic magnetite iron ore deposits, formed during ancient volcanic eruptions which released large amounts of magnetite which layer crystalized. Granite-associated deposits have been found in places like Malaysia and Indonesia which require very little post-processing to extract the iron. Titanomagnetite, a special class of magmatic magnetite iron ore, also serves as a source of titanium and vanadium, which is extracted via specialized smelters.
A third source of iron ore is in hematite ore deposits, which are found on all continents, especially in Australia, Brazil, and Asia. Most hematite ore originates from banded iron formations that have undergone chemical alteration over billions of years due to hydrothermal fluids. The world's largest producer of iron ore, Vale, located in Brazil, utilizes hematite ore. Vale produces 15% of the entire world's iron supply. In total, worldwide iron ore production is about one billion metric tons.
