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Earth Science

Natural Fluorine Does Exist ... In Smelly Rocks 80

scibri writes "Chemists have proved that a smelly rock is the only known place on Earth where fluorine exists in its elemental form, F2 (Abstract). The rock is antozonite, a calcium fluoride (fluorite) mineral that is dark violet or even black in colour, also known as fetid fluorite or stinkspar. Needless to say, this rock stinks. The pungent smell is given off when antozonite is crushed, and chemists and mineralogists have argued over the origin of the stench since the early nineteenth century. It turns out French chemist Henri Moissan, who first isolated fluorine in 1886, was right. The rock contains pockets of fluorine that are released on crushing."
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Natural Fluorine Does Exist ... In Smelly Rocks

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  • Re:Now you did it... (Score:5, Informative)

    by wierd_w ( 1375923 ) on Friday July 13, 2012 @10:37PM (#40645815)

    Not a chemist either, just a chemistry nerd, but:

    First. Its "Fluorine", not "flourine". No ground up wheat is involved. :D (sorry for the nitpick. Its an honest mistake.)

    Second, "fluorine" is the elementary pure form. Pure fluorine is a covelently bound pair of fluorine atoms, much like pure oxygen is.

    Fluoride is a salt made with fluorine that does not contain oxygen. Eg, "sodium fluoride": a sodium atom ionically attracted to a fluorine atom.

    When oxygen is involved, you get "fluorite", and "fluorate", depending on the number of oxygen atoms involved.

    Natural fluorites and fluorides occur in groundwater in far higher concentrations than are medicinally useful. Typically, the concentration of fluoride ion required to help stabilize the calcium phosphate complex found in teeth against acid breakdown is less than 1% in solution. (Toothpastes are usually sufficient to get the primary benefit of topical fluoride use, and usually contain .2% fluoride ion in the form of sodium fluoride by weight. Fluoridated water is higher, because the time the water is in contact with teeth while drinking is considerably shorter.) You can have way higher than this in naturally fluoride contaminated water supplies.

    High levels of fluoride in drinking water causes abnormal tooth and bone formation, in a condition known as fluorisis. It causes discolored, and fragile teeth, as well as brittle bones that are especially prone to osteoporosis and other bone disorders. As such, the danger of overfluoridation is indeed quite real. However, you would have to regularly eat your toothpaste to have this condition. It is argued that children, the primary reported benefactors to fluoridated water operations, are notoriously bad at proper use of brushing and toothpaste use, and are at significantly higher risk of ingesting the toothpaste instead of spitting it out. In conjunction with fluoridated water, this results in a higher risk of permanent tooth deformities in adult tooth formation from the excess fluoride.

    In areas with already dangerous levels of fluoride present in the drinking water from natural sources, the use of a filter to remove the excessive ion concentration is not only beneficial, but highly recommended, as it can indeed cause severe and debilitating tooth and bone problems.

    The more you know!

Each honest calling, each walk of life, has its own elite, its own aristocracy based on excellence of performance. -- James Bryant Conant