For the last 40 years, every Grammy trophy has been crafted by John Billings and his crew in a 2,000 square-foot facility in Ridgeway, Colorado. The New York Times had a nice feature on him.
The awards are made of a custom metal alloy called grammium (yes, really), and are cast from three molds: one for the base, one for the gramophone cabinet and one for the tone arm, which holds the bell. After the pieces are cast, they go through a series of filing, sanding and polishing processes, and the gramophone cabinet and tone arm are plated in 24-karat gold.
Once dry, the three pieces are assembled, and each award is laser-etched with a unique serial number for authenticity. The Grammys used during the television broadcast are for show; Mr. Billings and his team engrave the names of winners onto plates after the event.
The full story can be found here.