Superb portrait miniature of a naval officer c.1770 attributed to John Smart.
It has been suggested the sitter is likely to  be Captain John Williamson (1745-1798). A sketch of Williamson by Smart was sold Sothebys London 28th April 2021 lot 476. He was an officer on Captain James Cook’s third voyage.
The miniature is housed in the original small scale gold bracelet clasp with a later pendant fitting. 
Small area of discolouration to the background and light scratching  to the glass.
Miniature 2.6 cms by 2.3 cms.