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Salt crystals and ions

  1. Sep 19, 2008 #1
    I'm not sure where this question belongs, maybe in chemistry? move it if necessary.
    so the quest is this

    I have a salt crystal lamp. it is a large block of salt on a wood base with a light bulb inside a hollow in the salt. the selling point of these lamps is that the heat from the lightbulb causes negative ions to be emitted from the salt. (suposedly a health benefit but I don't believe it) My question is, would a warm lamp inside a large salt crystal actually cause negative ions to be emitted from the salt? or is that just clever advertising to the sientifically illiterate public? by the way.. I didn't purchase it :P
  2. jcsd
  3. Sep 19, 2008 #2

    Ivan Seeking

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    It sounds like nonsense.
  4. Sep 19, 2008 #3
    Sounds like nonsense to me too, but I didn't know enough physics to say wheather or not negative ions could be driven off the salt crystal by heating it. admittedly only a warm to the touch heat.
  5. Sep 20, 2008 #4


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    Heating can drive valence electrons out of the atom and out of the material. Vacuum tubes are based on this principle. Ions are created, but they remain in the crystalline structure.
    There is no way an ion could be separated from the material by the heat of a light bulb.
  6. Sep 20, 2008 #5


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    My sister got one of these a couple years ago as a Christmas gift from one of her FLAKY friends. At the time, the claim was something about it purifying the air or some silliness. On the upside, it's a pretty lamp. It gives a nice soft glow, like a candle, when lit. So, if you think it's worth the price for a decorative lamp, it works just fine as a lamp. As for cleaning the air or giving off any sort of ions...yep, gimmick for the gullible.
  7. Oct 21, 2008 #6


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    Salt Lamps

    Salt Lamp sold by Crystalite Salt
    edit...oops... http://www.dailymail.co.uk/health/a...-11-companies-making-false-health-claims.html

    Anyone making claims about their product should really have a public relations officer or direct line to the research department for inquiries such as the one above. I've seen these lamps in offices and living rooms and... I really have to restrain my "inner voice" from belting out...."give me a break"!

    Edit by Ivan: Merged with existing thread.
    Last edited by a moderator: Oct 21, 2008
  8. Oct 21, 2008 #7
    Re: Salt Lamps

    Ive never even heard of this.

    What exactly are "artificial electromagnetic waves"?
    Fake light? Bogus radio signals?
  9. Oct 22, 2008 #8


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    Re: Salt Lamps

    Sorry I was unaware of an existing thread about this. I would still say that this sort of claim and many other unsubstantiated claims like it would do well to be in the product claims section of PF.

    That said, something else occurred to me about this product and that was the fact that they are sticking a light bulb in the salt crystal that is supposed to be negating the effects of positive ions created by "artificial" electromagnetic waves (artificial?). The light bulb itself being a source of EMs. Hello? Slightly self-defeating?
  10. Oct 22, 2008 #9


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    With heat the compound does decompose to produce the respective ions - both positive and negative - however the amount of heat required corresponds to great temperatures. Even if the lamp is encased in the crystal the temperature may not suffice.

    The compound first melts then instead of going into the gaseous state it decomposes into ions.

    I am not certain if electromagnetic waves can cut of the individual ions from the bonding lattice - besides lasers. Unless there is some sort of quantum short cut the Hess steps need to be regarded. It has been a while since I had to deal with this stuff.
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