Watches worth more than £500,000 were stolen by an armed gang during a raid in Gleneagles.
Police revealed the value today during a fresh appeal for information.
It was also announced a UK-wide hunt has been launched to find those responsible.
Three men threatened staff with a firearm during the raid in Perthshire on June 27 and made off with more than 50 Rolex watches.
The gang targeted the Mappin and Webb jewellers at Gleneagles Hotel, using a sledgehammer to smash display cabinets before making off with the watches in a dark blue Audi.
The car was later found abandoned in Auchterarder.
Officers believe the thieves then used another car to leave Perthshire, a grey Range Rover Evoque, which was found burnt out in Glasgow the following day.
Detective Chief Inspector Andy Patrick, who is leading the probe, said the getaway cars had been stolen in England in the weeks leading up to the crime.
The Audi was taken from an address in Kent in June while the Range Rover was stolen in London in May — with both being given cloned number plates before being used in the “organised” theft.
DCI Patrick said a firearm was presented at staff during the robbery, adding: “Thankfully, no shots were fired, and no one was injured.”
He added: “It’s an organised crime, with a level of pre-planning around it.”
Police released images of the watches stolen and a picture of the hammer which was used to smash the glass cabinets in the shop.
The hammer was an Am-Tech 4lb sledge hammer with a fibreglass shaft.
DCI Patrick said: “I would appeal to anyone who knows where this item was purchased to contact us.
“I would also appeal to anyone who is offered the watches for sale to contact us, particularly jewellery stores, pawnbrokers or shopkeepers.
“This has been very terrifying for the staff and also the people within the premises, customers of the hotel.
“At 11 o’clock in the morning, the reception area was busy with people going about their business, checking out and such like. They were very traumatised by what took place.”
DCI Patrick said the hotel had been providing counselling and support to customers and staff.
Anyone with any information should contact Police Scotland on 101, or alternatively contact Crimestoppers anonymously on 0800 111 999.