An emerald ring with a gold setting valued at $500,000, which was part of the treasure of the 17th-century Spanish galleon Nuestra Señora de Atocha, has been found in the waters off Key West, Florida, the company Mel Fisher's Treasures said.

The precious jewel was found Thursday by a team of treasure-hunting divers who continue to search for remains of the gold-and-silver-laden Spanish galleon that sank in 1622.

Divers from the JB Magrudel ship also recovered several silver objects.

The ring measures 4.5 centimeters tall by 4.7 centimeters wide (1 3/4 inches tall by almost 2 inches wide), and has an elaborate design with initials engraved on the inner surface of the gem, just under a piece of the gold mount holding the emerald.

"These artifacts were recovered within 300 feet of where the gold rosary and gold bar were found earlier this year. It is exciting because we are moving into virgin territory, an area of the Atocha Trail that has never been worked," Magrudel skipper Andy Matroci said in a Fisher's Treasures press release.

A large part of the Atocha treasure, made up of more than 100,000 Spanish silver coins and valued at $450 million, was discovered in 1985 by treasure hunter Mel Fisher, who died in 1998 at the age of 76.

Fisher's descendents, who own the rights to the shipwrecked galleon, continue their search for the rest of the Atocha's treasure.

The company's vice president, Sean Fisher, who was on the Magrudel when the ring was discovered, said that the jewel is "the most significant artifact I have personally seen them bring out of the water."

It is estimated that some 400 silver ingots and more than 100,000 coins from the Atocha could still be at the bottom of the sea.