Here's what he said about it: "The iridescence is satin on the exterior, with just a dusting of silver on the interior. It measures 5 3/8-inch crimp-to-crimp, 5 1/4-inch side-to-side; 2 1/4-inches tall. The exterior has a smooth 1/4-inch band below the rim, then a 1 1/4-inch ribbed band to the horizontal mold line where the ribs transition to a diamond point design; the base is starred. The interior has the same smooth and ribbed bands (ribs are broader), transitioning at the mold line to concentric stepped-down bands (the "Threads") overlain with a six-petal outline."

Possibly made by Sowerby.