“Nice lenticular Stone bead” said Robert Liu on this one, when I asked him about it. Turns out there is one in Robert's reference text, Collectible Beads on page 98.
I had to look up what lenticular meant in relation to a bead and I found it in an old bead definition reference from Peter Francis. “Usually pertaining to the cross section of a bead resembling a double convex lens or the section of a lentil.”
Circa 1100 A.D. or earlier.
Beautiful markings. Tabular. Chipped on one side at hole. Wear on edges.
Sourced by Rita in the 1980’s.
Measures 51mm x 41mm. 28 grams.
Antiquities Item 118c