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Talc in Plastics
In 2011, about 26% of the talc consumed in the United States was used in the manufacturing of plastics. It is mainly used as a filler. The platy shape of talc particles can increase the stiffness of products such as polypropylene, vinyl, polyethylene, nylon, and polyester. It can also increase the heat resistance of these…
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Uses of Talc
Most people use products made from talc every day; however, they don’t realize that talc is in the product – or the special role that it plays.
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Talc Mining and Processing
Most talc in the United States is produced from an open-pit mine where the rock is drilled, blasted, and partially crushed in the mining operation. The highest grade ores are produced by selective mining and sorting operations. Great care is taken during the mining process to avoid contaminating the talc with other rock materials. These…
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How Does Talc Form?
Talc is a mineral that is most often found in the metamorphic rocks of convergent plate boundaries. It forms from at least two processes. Most large talc deposits in the United States formed when heated waters, carrying dissolved magnesium and silica, reacted with dolomitic marbles. A second process of talc formation occurred when heat and chemically active fluids altered rocks…
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Buying Sugilite
A person interested in purchasing sugilite jewelry, loose stones, or cutting rough should be very familiar with the material. The conditions of the gem that they might encounter are listed below: 1) Natural sugilite: This is a naturally occurring material that consists entirely of natural sugilite. Attractive pieces of this material should sell for the highest…
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Where is Talc Produced?
In the United States, talc consumption has slowly declined since 1995. Smaller amounts of the mineral are used in the ceramics industry because of a change in firing technology. In the paint industry, a shift from oil-based paints to latex paints has decreased the use of talc. In the cosmetics industry, many manufacturers have replaced…
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Geologic Occurrence of Sugilite
Sugilite occurs in only a few locations worldwide. Production of gem-quality sugilite only occurs in noteworthy amounts from the stratiform manganese deposits in South Africa. Sugilite is also found in small amounts as a primary mineral in igneous rocks and as a secondary mineral in marble. Manganese deposits similar to those of South Africa exist in other…
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Imitation Sugilite
Imitation sugilite and composite materials made to imitate sugilite are abundant in the marketplace. These items are often sold without disclosure. Much imitation sugilite is also labeled as “synthetic”. It is likely that sellers are unaware of what they are selling. The Gemological Institute of America reports that dyed marble and dyed quartzite have been used as sugilite…
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What is Talc?
Talc is a hydrous magnesium silicate mineral with a chemical composition of Mg3Si4O10(OH)2. Although the composition of talc usually stays close to this generalized formula, some substitution occurs. Small amounts of Al or Ti can substitute for Si; small amounts of Fe, Mn, and Al can substitute for Mg; and, very small amounts of Ca can substitute…
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Talc: A Mineral in Your Daily Life
Most people are familiar with the mineral known as “talc“. It can be crushed into a white powder that is widely known as “talcum powder.” This powder has the ability to absorb moisture, absorb oils, absorb odor, serve as a lubricant, and produce an astringent effect with human skin. These properties have made talcum powder an important…