Mosaic panels could be bought unmounted and then set as jewellery once the traveller returned home. The lack of a unifying theme in this necklace, with its Roman ruins, floral bouquets and dogs, suggests that it was perhaps not assembled by a Roman jeweller, but was a more individual and personal selection.

The term 'micromosaic' is used to describe mosaics made of the smallest glass pieces. Some micromosaics contain more than 5000 pieces per square inch. The earliest attempts at micromosaic revealed visible joins between the pieces (known as tesserae) and a lack of perspective. Later artists such as Antonio Aguatti made huge advances in micromosaic technique, resulting in renderings that were truer to life. Glass micromosaic technique developed in the 18th century, in the Vatican Mosaic Workshop in Rome, where they still undertake restoration work today.

Sir Arthur Gilbert and his wife Rosalinde formed one of the world's great decorative art collections, including silver, mosaics, enamelled portrait miniatures and gold boxes. Arthur Gilbert donated his extraordinary collection to Britain in 1996.