This is a beautiful pearlware pot de creme cup dated about 1790. These cups were sold as custard cups during this time. Pearlware was developed by Josiah Wedgwood around 1778. At this time most of the factories were producing products made of a softer creamware and pearlware was created to be an improvement.
The style of this cup is referred to as an "artichoke" cup which was originally produced by the St. Cloud factory in the early 1700's. Those early cups in this shape were often sold as little pots for ladies face cream "pots a fard". Staffordshire later produced them with and without handles as custard cups (pots de creme).
The cup pictured measures: 2 1/2" in maximum diameter x 2 3/4" in total height.
There is a blue mark on the bottom of the cup, see images.
Credits: Ulla Staford