Chemical substance found in Fluorite

I need to come up with a source of the chemical substance found in fluorite. I was wondering if anyone had any chemical knowledge on how to convert villiaumite and calcite, to the chemical substance (found in fluorite), using water and hydrochloric acid.

I was wondering if you could provide a detailed description of how we can prepare the desired chemical substance using these materials.

Confused student,
Thank you

chemically, fluorite is calcium fluoride (CaF2) and villiaumite is sodium fluoride (NaF). It is possible to break down both into their elemental components, but I would strongly recommend against trying. Both will liberate fluorine gas, which is EXCEEDINGLY TOXIC. Elemental calcium and sodium are also very reactive and flammable in the presence of water.

It's not completely clear what he/she wants to do, but my impression was they want to synthesize fluorite from calcite and NaF, in which case they just need to dissolve the calcite in any weak acid and then add the villiaumite, or a villiaumite solution in water? Nothing dangerous, unless they drink the leftover villiaumite.

The way I think of it. Dissolve "appropriate" amount of NaF (villiaumite) and CaCO₃ in a "sufficiently" acidous solution of HCl. If all goes well and you've done your calculations right the result would/should be solid CaF₂, saltwater and some gaseous CO₂.
Long time ago since I did any chemistry so please don't hold this against me.

cheers

Thanks for the help! I'm sorry if i was a little unclear, but your responses have answered my question perfectly. Now time to experiment!

Fluorite guy,
Where did you get your villiaumite?

Rock Currier
Crystals not pistols.

I need to first disassociate the Calcite molecules with a solution of HCl:

CaCO3(s) + 2HCl(aq) --> CaCl2(aq) + CO2(g) + H2O(l)

With the products shown, I can then add them to Villiaumite in the equation:

CaCl2(aq) + CO2(g) + H2O(l) + 2NaF(aq) --> CaF2(s) + 2NaCl(aq) + CO2(g) + H2O(l)

With my solution i can wait until it precipitates and then vacuum filter in and catch the precipitant on filter paper.

Since the solubility of CaF2 is not that low as it would appear from a cursory look at the solubility product (note the stoichiometry), you also need to consider that a certain amount of fluoride will stay in solution. This can be considerable if you are working with small amounts of sample in a large volume of solution (i.e. at low concentration). Increasing the concentration too much may turn out to be counter-productive as well, since the amount of impurities will incorporated in the lattice of your CaF2 precipitate will increase with concentration.

The Mindat data page for Villiaumite has this to say about the substance, so I would say it is not something to be casually messing with.


Poisonous! May be fatal if swallowed or inhaled. Affects respiratory system, heart, skeleton, circulatory system, central nervous system and kidneys. Causes irritation to skin, eyes and respiratory tract. Irritation effects may be delayed.

Eric

United Kingdom, Cornwall

I admit NaF MSDS is really scary but yet they put this thing in chewalble NaF tablets for preventing tooth cavities and fluoride toothpastes (0.32% fluoride!).

Years ago, the MSDS for water used to say that it was toxic and - if ingested - treatment should be to give the casualty plenty of water to drink. . Thankfully, they've amended that now.

Alan