Glassblowing

[Zana Avaya Lykoi]

http://www.ehow.com/how-does_4706115_glass...nd-workday.html
not a lot of info.. but it actually tells you it's possible..

any type of container that wouldn't melt, clay based, brick based, that can contain heat can be used. The iron rods used to amplify the heat makes sense too..