The seal, a longitudinal one in green Jade, represents a roaring imperial lion with the mouth towards the sky. On the frontal part has one column of chinese characters. It seems to be from the Empress Wu Zetian (690-705).
I did my research, and find out: 些度產唐, Xiē dù chǎn táng, "Tang Dynasty". 唐 Tang 產 chan 度 Du 些 Xie
Please find attached the picture.
I would like confirmation.