A large emerald ring is pictured in the hand of Sean Fisher, in this photograph taken on June 23, 2011 and released on July 2, 2011. [Agencies]

KEY WEST, Florida - Divers in the Florida Keys have recovered a large emerald ring and two silver spoons believed to come from Nuestra Senora de Atocha, a shipwrecked Spanish galleon that has already yielded one of the greatest treasures ever recovered from the sea.

Employees of Mel Fisher's Treasure, the salvage company that has worked the shipwreck site since 1969, believe the latest haul signals they are close to finding the sterncastle, a key missing portion of the ship.

"The sterncastle is where the clergy and elite were with their personal items," said Sean Fisher, spokesman for the family business and grandson of its late founder, Mel Fisher.

The Atocha was headed back to Spain with a load of gold and silver from the New World when it sank and broke up in a hurricane not far from Key West in September 1622.

After a 16-year-search, Mel Fisher and his crew found the "mother lode" of the shipwreck in September 1985. They hauled up more than 40 tonnes of gold and silver, including more than 100,000 Spanish silver coins known as "Pieces of Eight," along with Colombian emeralds and other artifacts. The company estimated its worth at nearly $500 million.

Since then, Sean Fisher said the crew has made many other discoveries within a ten-mile (16-km) spread of the original site, and in a straight line.

"This tells us we are moving in the right direction," he said. "We have virgin territory around our search area and will be in there next."

After the original wreck, currents and additional hurricanes moved the broken parts around. "It broke in two and then banged around for hundreds of years and that is why what we are finding is scattered," Fisher said.

Ring Valued Initially at $500,000

He was on the company's salvage ship JB Magruder on June 23 when diver Tim Meade came up with the large square emerald mounted in a gold ring, whose worth the company estimates at $500,000.

Divers also came up with two silver spoons and other artifacts that will have to be treated at the Fisher labs in Key West before being exposed to fresh air. Unlike the gold ring, the other items are encrusted and a value can't be placed on them at this time.

"I think one item is a hinge and another is a lid, so it's possibly pieces from a jewelry box," Fisher said.

He has a copy of the Atocha's manifest and going by it, he expects to find at least 100,000 coins, 400 silver bars and personal jewelry at the sterncastle location.

"We have already found more gold than is on the manifest," he said with a smile. "There was a lot of smuggling so the clergy and nobility wouldn't have to pay the king's tax. We expect there will be many items around the sterncastle that are not on the manifest."

Fisher described the thrill of seeing and touching the treasure, and being the first person to do so in almost 400 years. "I was 15 when I found my first silver," Fisher said. "I was 17 when I first found gold. Silver is great, but gold shines, even after more than 300 years in the water."

The dive for treasure is a group effort, Fisher said. Two divers search the selected area at a time, while other crew members stay on deck. The whole crew participates and when the value of the search is determined, bonuses are given out.

Fisher said 90 percent of treasure hunting involved finding out where the treasure isn't.

"Technology has helped us above the water," he said. "Below the water our search hasn't changed much over the years."

The company uses "mailboxes," large round tubes on the stern of the salvage ship that force air below the waterline to blow away the top layer of debris and sand on the bottom.

The Magruder pulled into its slip at Safe Harbor Marina, outside Key West, last Thursday after discovering the ring and other artifacts about 35 miles away.

Fisher popped open a champagne bottle to celebrate even as the company's other 100-foot (30-meter) salvage ship, Dare, prepared to go out to continue the treasure hunt.

Each ship has a crew of six or eight and stays out about 10 days at a time, weather permitting.