Hydrofluoric acid....

[IrishEyes]

I''ve been reading alot about colored stones lately, and the topic of hydrofluoric acid keeps coming up in relation to it destroying many types of stones. What exactly is this substance, and why is it used (what is its primary purpose) ? Why does it destroy so much, is it that strong? Just wanted some additional info.
Thanks!

 

[Garry H (Cut Nut)]

Because it is both and acid and oxidant, so it will attack and disolve everything except platinum, some waxes and some plastics.
It can not be stored in glass (which it is used to etch patterns on etc).

We used it in geology to do assays etc - you crush the rock and put it in a plat cruciable in boiling water in a fume cabinet and disolve everything, then precipitate out each substance 1 by one or perform spectroscopic analysis etc.
It was hard to see into the cruciable to see if it was all disloved - students put heads inside and stood on a stool. one wiff and you had a 1 hour nose bleed.

 

[DoctorDan]

I heard some pretty horrible stories about HF and people in labs. When you use it you're supposed to be VERY careful, as only a little contacting the skin can be deadly. In a lab I used to work in, they had some kind of treatment cream ready to go in case something happened.

 

[IrishEyes]

Ack!!! Sounds pretty wretched!

Thanks for the feedback