This pretty aqua colored double egg cup was produced by Adams China of England. The Adams mark is located under the base cup, and dates from 1896 to the early 1900s. I have not been able to determine the name of the pattern. It has a floral design with pink, pale yellow and lavender flowers. The rim is bordered by yellow lines with a black rope design in the middle. The aqua color shows darker in the photos than in person. It is more the shade shown in the last photo.
The egg cup has no chips or cracks but does have light overall crazing. It stands 3.75" tall, with a base diameter of almost 2". The material from which it is made is often called Calyx Ware, a type of ironstone.