RAPAPORT... The Federation of Belgian Diamond Bourses has closed all four of Antwerp's trading floors following a spike in coronavirus cases in the city.The national government tightened social-distancing rules on Monday to prevent a repeat of the full lockdown it instituted during the first virus wave. The province of Antwerp is responsible for more than half of the country's new infections, and is now under home curfew between 11:30 p.m. and 6 a.m., local media reported. People may only use the trading halls as a passage, federation president Phillipe Barsamian said Monday in a letter to members. He also urged people to wear face masks to cover their mouths and noses in all communal areas of the bourse buildings, with a fine of EUR 250 ($293) - and potentially other disciplinary sanctions - for those who flout the rule. Members should preferably limit their gatherings on streets in the Antwerp diamond district to two people, Barsamian added.The impact of the closure is limited: Most trading takes place in offices and other parts of the bourse complexes. The Antwerp World Diamond Centre (AWDC) premises will remain open, as will the diamond office, Antwerp's customs center, which has been operational throughout the crisis, an AWDC spokesperson said. The shutdown also comes as the trade enters a summer vacation period, with dealers likely to be absent for several weeks.De Beers said its physical viewings of sight goods would still take place in Antwerp this week despite the situation.Antwerp has four diamond exchanges: the Antwerp Diamond Bourse, the Antwerpsche Diamantkring (for rough trading), the Diamond Club of Antwerp and the Vrije Diamanthandel. Their respective trading floors shut initially on March 16 when Belgium's coronavirus outbreak worsened, and reopened on May 11.However, the country has entered a second wave of Covid-19, with the number of new infections increasing 69% during the period from July 18 to 24 compared with the previous week, according to government figures. An average of 311 people tested positive each day during that period.The Israel Diamond Exchange also shut its trading floor last week as virus cases rose, but opened other rooms in which members can work and trade.Image: The Antwerp Diamond Bourse trading floor. (Antwerp World Diamond Centre)