The Sicpa Oasis validator system (bullion protect) is pictured on one kilogram bar of gold at Swiss refiner Metalor in Marin near Neuchatel, Switzerland July 5, 2019. Picture taken July 5, 2019. To match Special Report GOLD-SWISS/FAKES REUTERS/Denis Balibouse

The Sicpa Oasis validator system (bullion protect) is pictured on one kilogram bar of gold at Swiss refiner Metalor in Marin near Neuchatel, Switzerland July 5, 2019. Picture taken July 5, 2019. To match Special Report GOLD-SWISS/FAKES REUTERS/Denis Balibouse

The Sicpa Oasis validator system (bullion protect) is pictured on one kilogram bar of gold at Swiss refiner Metalor in Marin near Neuchatel, Switzerland July 5, 2019. Picture taken July 5, 2019. To match Special Report GOLD-SWISS/FAKES REUTERS/Denis Balibouse

The Sicpa Oasis validator system (bullion protect) is pictured on one kilogram bar of gold at Swiss refiner Metalor in Marin near Neuchatel, Switzerland July 5, 2019. Picture taken July 5, 2019. To match Special Report GOLD-SWISS/FAKES REUTERS/Denis Balibouse

The Sicpa Oasis validator system (bullion protect) is pictured on one kilogram bar of gold at Swiss refiner Metalor in Marin near Neuchatel, Switzerland July 5, 2019. Picture taken July 5, 2019. To match Special Report GOLD-SWISS/FAKES REUTERS/Denis Balibouse

The Sicpa Oasis validator system (bullion protect) is pictured on one kilogram bar of gold at Swiss refiner Metalor in Marin near Neuchatel, Switzerland July 5, 2019. Picture taken July 5, 2019. To match Special Report GOLD-SWISS/FAKES REUTERS/Denis Balibouse

The Sicpa Oasis validator system (bullion protect) is pictured on one kilogram bar of gold at Swiss refiner Metalor in Marin near Neuchatel, Switzerland July 5, 2019. Picture taken July 5, 2019. To match Special Report GOLD-SWISS/FAKES REUTERS/Denis Balibouse

The Sicpa Oasis validator system (bullion protect) is pictured over one kilogram bar of gold at Swiss refiner Metalor in Marin near Neuchatel, Switzerland July 5, 2019. Picture taken July 5, 2019. To match Special Report GOLD-SWISS/FAKES REUTERS/Denis Balibouse

The world's largest gold bullion coin, the Australian Kangaroo One Tonne Gold Coin, is displayed to mark the official launch of the Perth Mint Physical Gold Exchange Traded Fund (AAAU), outside the New York Stock Exchange (NYSE) in New York, U.S., July 16, 2019. REUTERS/Brendan McDermid

The world's largest gold bullion coin, the Australian Kangaroo One Tonne Gold Coin, is displayed to mark the official launch of the Perth Mint Physical Gold Exchange Traded Fund (AAAU), outside the New York Stock Exchange (NYSE) in New York, U.S., July 16, 2019. REUTERS/Brendan McDermid

A woman takes a selfie with the world's largest gold bullion coin, the Australian Kangaroo One Tonne Gold Coin, is displayed to mark the official launch of the Perth Mint Physical Gold Exchange Traded Fund (AAAU), outside the New York Stock Exchange (NYSE) in New York, U.S., July 16, 2019. REUTERS/Brendan McDermid

The world's largest gold bullion coin, the Australian Kangaroo One Tonne Gold Coin, is displayed to mark the official launch of the Perth Mint Physical Gold Exchange Traded Fund (AAAU), outside the New York Stock Exchange (NYSE) in New York, U.S., July 16, 2019. REUTERS/Brendan McDermid

A man takes a photo of the world's largest gold bullion coin, the Australian Kangaroo One Tonne Gold Coin, is displayed to mark the official launch of the Perth Mint Physical Gold Exchange Traded Fund (AAAU), outside the New York Stock Exchange (NYSE) in New York, U.S., July 16, 2019. REUTERS/Brendan McDermid

People photograph the world's largest gold bullion coin, the Australian Kangaroo One Tonne Gold Coin, is displayed to mark the official launch of the Perth Mint Physical Gold Exchange Traded Fund (AAAU), outside the New York Stock Exchange (NYSE) in New York, U.S., July 16, 2019. REUTERS/Brendan McDermid

A pedestrian walks past a window displaying a representation of a gold bar at a bullion broker in Piccadilly, London, Britain, December 11, 2017. REUTERS/Toby Melville

A pedestrian walks past a window displaying a representation of a gold bar at a bullion broker in Piccadilly, London, Britain, December 11, 2017. REUTERS/Toby Melville

Gold U.S. dollar bullion coins are seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

Gold U.S. dollar and Russian rouble bullion coins are seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

Gold U.S. dollar and Russian rouble bullion coins are seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

Gold U.S. dollar bullion coins are seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

Gold U.S. dollar bullion coins are seen in this photo illustration taken in Moscow, Russia August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

Gold U.S. dollar bullion coins are seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

Gold U.S. dollar and Russian rouble bullion coins are seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

A gold Russian rouble bullion coin is seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

A gold Russian rouble bullion coin is seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

A gold Russian rouble bullion coin is seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

A gold Russian rouble bullion coin is seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

Gold U.S. dollar bullion coins are seen in this photo illustration taken in Moscow, Russia, August 4, 2017. Picture taken August 4, 2017. REUTERS/Maxim Shemetov/Illustration

Gold bullions are displayed at GoldSilver Central's office in Singapore June 19, 2017. Picture taken June 19, 2017. REUTERS/Edgar Su

Gold bullions are displayed at GoldSilver Central's office in Singapore June 19, 2017. Picture taken June 19, 2017. REUTERS/Edgar Su

Gold bullions are displayed at GoldSilver Central's office in Singapore June 19, 2017. Picture taken June 19, 2017. REUTERS/Edgar Su

Gold bullions are displayed at Degussa shop in Singapore June 16, 2017. Picture taken June 16, 2017. REUTERS/Edgar Su

Gold bullions are displayed at Degussa shop in Singapore June 16, 2017. Picture taken June 16, 2017. REUTERS/Edgar Su

An employee shows gold bullions at Degussa shop in Singapore June 16, 2017. Picture taken June 16, 2017. REUTERS/Edgar Su

Gold bullions are displayed at Degussa shop in Singapore June 16, 2017. Picture taken June 16, 2017. REUTERS/Edgar Su

An employee shows gold bullions at Degussa shop in Singapore June 16, 2017. Picture taken June 16, 2017. REUTERS/Edgar Su

An employee shows a gold bullion bar at Degussa shop in Singapore June 16, 2017. Picture taken June 16, 2017. REUTERS/Edgar Su

Gold bullions are displayed at GoldSilver Central's office in Singapore June 19, 2017. Picture taken June 19, 2017. REUTERS/Edgar Su

An employee puts gold bullions into a safe deposit box at Degussa shop in Singapore June 16, 2017. Picture taken June 16, 2017. REUTERS/Edgar Su

A worker places gold bullion on display at Hatton Garden Metals precious metal dealers in London, Britain July 21, 2015. Gold was on the brink of five year lows on Tuesday, with more losses expected in the coming months following Monday's "bear raid" when sellers dumped an estimated 33 tonnes in just two minutes. REUTERS/Neil Hall

Gold bullion is displayed at Hatton Garden Metals precious metal dealers in London, Britain July 21, 2015. Gold was on the brink of five year lows on Tuesday, with more losses expected in the coming months following Monday's "bear raid" when sellers dumped an estimated 33 tonnes in just two minutes. REUTERS/Neil Hall

A woman is reflected in a mirror as she tries on a necklace at a jewellery showroom on the occasion of Akshaya Tritiya, a major gold buying festival, in Kolkata April 21, 2015. Gold purchases in India started slowly on Tuesday, a festival day, despite a fall in local prices, as hard times in rural areas have hit demand and many buyers are holding back because they expect prices to fall even further. Indians are the world's biggest consumers of bullion and Akshaya Tritiya celebrated on Tuesday is usually one of the busiest gold-buying festivals along with Diwali and Dhanteras. REUTERS/Rupak De Chowdhuri

Gold bracelets are on display as a woman (L) makes choices at a jewellery showroom on the occasion of Akshaya Tritiya, a major gold buying festival, in Kolkata April 21, 2015. Gold purchases in India started slowly on Tuesday, a festival day, despite a fall in local prices, as hard times in rural areas have hit demand and many buyers are holding back because they expect prices to fall even further. Indians are the world's biggest consumers of bullion and Akshaya Tritiya celebrated on Tuesday is usually one of the busiest gold-buying festivals along with Diwali and Dhanteras. REUTERS/Rupak De Chowdhuri

A gold necklace is displayed as a salesman waits for customers inside a jewelry showroom on the occasion of Akshaya Tritiya, a major gold buying festival, in the old quarters of Delhi April 21, 2015. Gold purchases in India started slowly on Tuesday, a festival day, despite a fall in local prices, as hard times in rural areas have hit demand and many buyers are holding back because they expect prices to fall even further. Indians are the world's biggest consumers of bullion and Akshaya Tritiya celebrated on Tuesday is usually one of the busiest gold-buying festivals along with Diwali and Dhanteras. REUTERS/Adnan Abidi

A salesman is reflected in a mirror inside a gold jewellery showroom on the occasion of Akshaya Tritiya, a major gold buying festival, in the old quarters of Delhi April 21, 2015. Gold purchases in India started slowly on Tuesday, a festival day, despite a fall in local prices, as hard times in rural areas have hit demand and many buyers are holding back because they expect prices to fall even further. Indians are the world's biggest consumers of bullion and Akshaya Tritiya celebrated on Tuesday is usually one of the busiest gold-buying festivals along with Diwali and Dhanteras. REUTERS/Adnan Abidi

A woman checks gold bangles inside a jewelry showroom on the occasion of Akshaya Tritiya, a major gold buying festival, in the southern Indian city of Kochi April 21, 2015. Gold purchases in India started slowly on Tuesday, a festival day, despite a fall in local prices, as hard times in rural areas have hit demand and many buyers are holding back because they expect prices to fall even further. Indians are the world's biggest consumers of bullion and Akshaya Tritiya celebrated on Tuesday is usually one of the busiest gold-buying festivals along with Diwali and Dhanteras. REUTERS/Sivaram V

A customer looks at gold ornaments on display inside a jewelry showroom on the occasion of Akshaya Tritiya, a major gold buying festival, in the southern Indian city of Kochi April 21, 2015. Gold purchases in India started slowly on Tuesday, a festival day, despite a fall in local prices, as hard times in rural areas have hit demand and many buyers are holding back because they expect prices to fall even further. Indians are the world's biggest consumers of bullion and Akshaya Tritiya celebrated on Tuesday is usually one of the busiest gold-buying festivals along with Diwali and Dhanteras. REUTERS/Sivaram V

A police officer holds a small bullion coin version of the world's largest gold coin, made by Perth Mint based in Australia, which is on promotional display in Munich January 26, 2014. The coin is 80 cm in diameter, weighing in at just over one tonne. The 99.99 percent pure gold coin has been valued at more than $50 million. REUTERS/Michael Dalder (GERMANY - Tags: BUSINESS SOCIETY)

A shopkeeper waits for customers at his gold and silver jewellery shop in the old quarters of Delhi October 7, 2013. Gold nudged up in Asian trading on Monday as the near-week long U.S. government shutdown raised fears Congress may struggle to raise the debt ceiling in time, burnishing bullion's safe-haven appeal. REUTERS/Mansi Thapliyal (INDIA - Tags: BUSINESS COMMODITIES)

A craftsman polishes a gold necklace at a workshop in New Delhi September 6, 2013. Gold held near a 2-week low on Friday and was headed for its second week of losses on growing expectations the U.S. Federal Reserve will soon wind down its commodities-friendly bond-buying programme. India's gold demand picks up between August and October, when consumers buy bullion to celebrate festivals, which peak with the Diwali festival of lights in November. REUTERS/Anindito Mukherjee (INDIA - Tags: BUSINESS)

A craftsman makes a gold necklace at a workshop in New Delhi September 6, 2013. Gold held near a 2-week low on Friday and was headed for its second week of losses on growing expectations the U.S. Federal Reserve will soon wind down its commodities-friendly bond-buying programme. India's gold demand picks up between August and October, when consumers buy bullion to celebrate festivals, which peak with the Diwali festival of lights in November. REUTERS/Anindito Mukherjee (INDIA - Tags: BUSINESS)

A craftsman makes a gold necklace at a workshop in New Delhi September 6, 2013. Gold held near a 2-week low on Friday and was headed for its second week of losses on growing expectations the U.S. Federal Reserve will soon wind down its commodities-friendly bond-buying programme. India's gold demand picks up between August and October, when consumers buy bullion to celebrate festivals, which peak with the Diwali festival of lights in November. REUTERS/Anindito Mukherjee (INDIA - Tags: BUSINESS)

A craftsman makes a gold ornament at a workshop in New Delhi September 6, 2013. Gold held near a 2-week low on Friday and was headed for its second week of losses on growing expectations the U.S. Federal Reserve will soon wind down its commodities-friendly bond-buying programme. India's gold demand picks up between August and October, when consumers buy bullion to celebrate festivals, which peak with the Diwali festival of lights in November. REUTERS/Anindito Mukherjee (INDIA - Tags: BUSINESS)

Excavation expert Juan Diaz (C) says a prayer, facing the pit before retiring a search for gold bullion, believed to have been buried during the 1864-1870 War of the Triple Alliance, at an excavation site in Aldana Canada city, 29 km (18 miles) from Asuncion August 8, 2013. According to local media, Diaz has been charged by district attorney Cynthia Lovera for environmental crimes due to excavating without a license. REUTERS/Jorge Adorno(PARAGUAY - Tags: SOCIETY)

District attorney Cynthia Lovera (2nd R) visits a site where excavation expert Juan Diaz has been searching for gold bullion, believed to have been buried during the 1864-1870 War of the Triple Alliance, at an excavation site in Aldana Canada city, 29 km (18 miles) from Asuncion August 5, 2013. According to local media, the excavation has been ordered to stop and Diaz has been charged by Lovera for environmental crimes due to excavating without a license. Picture taken August 5, 2013. REUTERS/Jorge Adorno (PARAGUAY - Tags: SOCIETY)

District attorney Cynthia Lovera (front C) visits a site where excavation expert Juan Diaz has been searching for gold bullion, believed to have been buried during the 1864-1870 War of the Triple Alliance, at an excavation site in Aldana Canada city, 29 km (18 miles) from Asuncion August 5, 2013. According to local media, the excavation has been ordered to stop and Diaz has been charged by Lovera for environmental crimes due to excavating without a license. Picture taken August 5, 2013. REUTERS/Jorge Adorno (PARAGUAY - Tags: SOCIETY)

People watch as an excavator fills up a site where excavation expert Juan Diaz has been searching for gold bullion, believed to have been buried during the 1864-1870 War of the Triple Alliance, at an excavation site in Aldana Canada city, 29 km (18 miles) from Asuncion August 8, 2013. According to local media, the excavation has been ordered to stop and Diaz has been charged by district attorney Cynthia Lovera for environmental crimes due to excavating without a license. REUTERS/Jorge Adorno (PARAGUAY - Tags: SOCIETY)

People watch as an excavator fills up a site where excavation expert Juan Diaz has been searching for gold bullion, believed to have been buried during the 1864-1870 War of the Triple Alliance, at an excavation site in Aldana Canada city, 29 km (18 miles) from Asuncion August 8, 2013. According to local media, the excavation has been ordered to stop and Diaz has been charged by district attorney Cynthia Lovera for environmental crimes due to excavating without a license. REUTERS/Jorge Adorno (PARAGUAY - Tags: SOCIETY TPX IMAGES OF THE DAY)

Excavators fill up a site where excavation expert Juan Diaz has been searching for gold bullion, believed to have been buried during the 1864-1870 War of the Triple Alliance, at an excavation site in Aldana Canada city, 29 km (18 miles) from Asuncion August 8, 2013. According to local media, the excavation has been ordered to stop and Diaz has been charged by district attorney Cynthia Lovera for environmental crimes due to excavating without a license. REUTERS/Jorge Adorno (PARAGUAY - Tags: SOCIETY)