Thank you for using the Jiskha Homework Help Forum. I'm not sure what exactly you need in the way of "extraction of a crayon" but h opefully the following will help you. If it doesn 't is there a "contact us" on the Crayola website so that you might ask them?
2. (PDF file to download about museum artifacts):
You can, of course, melt down the crayons but why would you?
Paraffin wax is made from petroleum. Pigments are made from different chemicals, such as sulfur. Check these sites for more information.