growing colored crystals

[brittnee]

I tried to grow color alum crystals for my science fair project last year and it didn't turn out the way I wanted it to. The crystals were still clear after I finished the project.I tried using food coloring. I want to know if we need to color the seed crystals and how to do that. Also, I found a sugar rock candy crystal project that uses food coloring and it appears that the crystals come out colored - is there something about sugar that makes this happen? Any suggestions?

[deleted-81090]

Hi Brittnee, sorry to hear your science project didn't turn out how you wanted!

This project sounds really cool though! It is possible to color alum crystals, so lets try to figure out what went wrong before! From what I've read it looks like you do need to color the seed crystals! Here is an experiment I found where they used food coloring to color the seed crystals:

http://www.ehow.com/how_4914442_make-ow ... stals.html

I also found a really cool experiment for making glow in the dark crystals where you use a highlighter to color the seed crystals. Its a little more complicated but still looks fun!

http://chemistry.about.com/od/crystalre ... ystals.htm

Was your experiment similar to these ones? Or did you add the food coloring at a different step?

Sugar and alum crystals have different formulas so interact differently. But, I can't find any information about why sugar would be easier to color than alum. Comparing the two could be a cool science experiment though if you want to try it!

Hope this helps and let me know if you have any more questions!
Anna

[brittnee]

thankx we added the food coloring after the seed crystals were done.last year i did see the glow in the dark crystal project be my teacher said that was a very easy project and i wanted a hard one.this year i want ed to try and see what i really did wrong so this time i might add the food coloring during the seed crystals.thats why im on this thing to see if i can get any suggestion about it.