After displaying his collection of 39 natural and synthetic gemstones for nearly 25 years at his home, gem enthusiast Donald Milliken has donated the entire collection—valued at $25,000—to the Gemological Institute of America (GIA).

“We’re getting on in years, and I didn’t know what I would do with them,” Milliken said. “I didn’t want to sell them, so GIA was the logical place to turn them over to.” Milliken, who is 94, personally faceted all of the stones in the collection, a hobby he took up when he was in his 70s.

According to GIA Museum director Elise Misiorowski, Milliken’s collection will be an important educational tool, giving students an example of precise gemstone cutting.

The collection, housed in a specially built wooden case, is crowned with a 311.5-ct. fluorite on which Milliken faceted 58 step cuts. Also in the collection are a 4-ct. kite-cut tourmaline, a 40-ct. shield-cut fluorite, and a 100-ct. twin-pavilion corundum.

Milliken’s hobby has won him recognition from several regional gemological organizations, including the California Federation of Mineralogical Societies. In 1976, Milliken’s collection won the Best Case – Faceted Stones category at the San Francisco California Federation Show.