Re: Is there a chemical that can make fire turn white?

Yes, different chemicals turn the flames of a fire into different colors;
this approach is used as a method to identify chemicals - a method called 
flame photometry.  Here is a website that lists some of the flame colors 
associated with various chemicals - you will note that zinc can be used to 
make the flames turn white:
Qualitative 
Analysis - Chemistry Flame Tests
This site says that barium sulfate (barite) gives a  small amount of white 
light:
Flame 
Colors

You can see some photographs of various colored flames from that site:


This site has some movies of various colored flames:

http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA2/MAIN/FLAME/CD2R1.HTM