In Pictures: Here’s how Apple is spending $1 billi...
This schematic outlines how GTAT's AFS creates the raw sapphire. Sapphire is a variety of the mineral corundum (or aluminum oxide). The process starts with a seed sapphire crystal that has a specific crystalline orientation. The aluminum oxide growth mixture is added, and heated to its melting point of 2,040 degrees Centigrade. For the AFS, heat is then extracted from the bottom up until the growth is complete. The entire process takes about 15 days.
In Pictures: Here’s how Apple is spending $1 billion on sapphire