For comparison, here is a contemporary purple malachite cup and saucer set by Sowerby – pattern number 1400, RD 323400 (registered on 8 July 1878).
(Permission for the re-use of these images on the GMB granted by iandubh).
The exterior surface of the cup and saucer is decorated with panels with a linear pattern crossing at an angle, though the actual design registration was for a handled posy basket with similar surface decoration (and which appears in the Sowerby pattern books as pattern 1325 or 1325½, depending on whether the handles are closed or open). I’ve seen several examples of this Sowerby cup and saucer set, and always in purple malachite.
This is yet another example of Sowerby and Greener producing very similar designs at about the same time - spies in the camp or just sufficient differences in the design to deflect accusations of plagiarism?
Fred.