A rare Chelsea aubergine ground bowl

A rare Chelsea aubergine ground bowl, the exterior richly gilded with three chinoiserie panels, divided by elaborate Rococo trellis-work, the interior also with an aubergine coloured glaze and with a rubbed gilt central panel, a gold anchor mark, c.1765. Some rubbing to the gilding. 22.5cm. This very unusual ground colour is perhaps intended to simulate amethyst coloured glass.