Deep South Glass is the name of a store in the 2002 movie "Sweet Home Alabama" that sells items made from fulgurites. Fulgurites are hollow glass tubes formed during lightning strikes.
It's important to note that the fulgurites depicted in "Sweet Home Alabama" are not real fulgurites, but manufactured ones. Real fulgurites are extremely fragile and seldom clear. Fulgurites are formed when lighting strikes sand, specifically quartzose sand or silica. When lightning strikes, the sand is instantly melted and fused together. When it cools, fulgurite is formed. It takes temperatures of over 1,800 degrees Celsius to fuse the various minerals together. Fulgurites can even form when lightning hits rocks, causing them to undergo the same process that creates sand fulgurites.