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Annealing and Quenching 
Annealing is the process of 'resetting' a metal's crystal
structure. Annealing causes internal stresses in a metal to be relaxed,
by allowing the atoms in the solid to rearrange themselves in a lower
stress state. The effect of this is that the metal gets softer, because
any work hardening or other hardening is removed. At a dark
red temperature (650°C), annealing takes place in a few
seconds. At that point, new crystals begin to form, or nucleate
in the gold. As the crystals grow, they make the metal more prone to
cracking, so we want to 'freeze' the crystal structure in the
annealed state. We do this by quenching, or rapidly
cooling the metal by throwing it in water: Cooling the crystal structure causes the atoms to 'freeze' in position, and stops the small crystals from growing. The smaller the crystals, or grain size, the easier it will be to work. Quench your billet as soon as the red color disappears from the metal. After quenching the billet looks like this:  This is because the gold oxidized in the air while it was being heated. This oxide (along with that pesky White-Out) will have to be removed in the next step.
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