A priceless prehistoric gold lozenge excavated in the 19th century will be put on public display for the first time when the new Neolithic gallery at Wiltshire Heritage Museum in Devizes opens next year.

The museum was awarded a £370,000 grant from the Heritage Lottery Fund earlier this year to finance the new gallery, which will be built at the rear of the museum and is due to open in May.

Secure display units will enable the museum to show items that were thought too valuable for public display.

Foremost of these is the large gold lozenge that was found in the Bush Barrow grave near Stonehenge, dating from around 1900BC, which was excavated by William Cunnington in 1808.

David Dawson, director of the museum, said: “A replica of the lozenge has always been on display here but as far as I am aware the original has never been put on show.

“The HLF grant has now enabled us to afford high- security measures.”

Other items from the grave to be put on show are a mace, the head of which was made from a rare flecked fossil stone from Devon, while the handle was embellished with bone zigzag mounts, and a smaller lozenge, which may well have been mounted on the handle of the mace.

There are also more recent finds in the new galleries including items from the grave of the Roundway Warrior, also excavated by William Cunnington in 1855, items from an Anglo-Saxon cemetery that was excavated in 1991 and artefacts from a dig by the Army at Barrow Clump near Figheldean on Salisbury Plain earlier this year.

Building work on the new galleries is due to begin in December and the fitting out is scheduled to run from January to the end of March. The objects will be installed during April, ready for the grand opening in May.

Dr Dawson said: “We want to open the galleries in time for our summer season.”