These are 5 antique sulphides - cameos of unglazed white porcelain encased in transparent glass set against a dark background.
They date to c1800 and look to have been removed from settings as the backs show signs of wear / glue.
Four are in excellent condition but the largest shows lighter areas where the backing has separated from the glass.
The largest measures 2 x 1.5 cm
The smallest 1 x 1.2cm
Stock no. GD39