An impeller for a pump is described, the impeller including: an impeller body formed from a ceramic material and including pumping vanes; an impeller hub formed from a metallic material; the impeller hub includes a central boss arranged to engage with a pump driveshaft wherein the hub further includes a series of projections which are spaced away from the axis of rotation of the hub and the projections engage with apertures in the impeller body; and wherein the projections and corresponding apertures are spaced away from the axis of rotation by a distance of no more than 70% of the radius of the impeller.
