Archie Newnham-Dibley with the secret drawer and the bureau. A brooch containing 75 diamonds and 34 emeralds, was found inside of this caravan in Cornwall. The brooch could be worth £100,000. See SWNS story SWGEM; A charity for inner city kids had a ‘Del Boy’ moment after a broach worth tens of thousands of pounds was found inside a battered desk – in a run-down CARAVAN. The precious gem contains 75 diamonds and 34 emeralds and was discovered hidden in a secret drawer of a 19th-century bureau. The furniture was in a caravan on a farm in Dartmoor in Devon belonging to the Shallowford Trust, a charity giving inner-city children an experience of countryside life.