Essex Police were contacted following reports that criminals had targeted Bonds of Brentwood on Ingrave Road.
The attack happened when four men on mopeds – two on each bike – rode up to the shop and used axes to smash their way in.
They helped themselves to a haul of jewellery, worth a five figure sum, before fleeing the scene on their bikes.
The two mopeds – one bronze and silver in colour and the other black and grey – were later recovered in a play area just off Cromwell Road, Brentwood.
Police are now investigating the incident and are appealing for any witnesses to come forward.
Det Sgt David Wilkinson of Brentwood CID said: “We would like to hear from anyone who witnessed the robbery and anyone who may have captured footage or images of the incident and suspects on their phones.
“Equally we would like to hear from anyone who may have seen the suspects in the Cromwell Road area where the mopeds were later found. Your help could be vital in helping us catch those responsible.”
No-one was injured during the incident.
Witnesses to the incident or anyone with footage and images can contact detectives at Brentwood CID on 101 or Crimestoppers anonymously on 0800 555 111.