I am very new to this. We have a dark brown high gloss glazed bowl, oval,61/2″ by 71/8″ top,41/2″ bottom diameter – 31/2″ high. Ribbed on the outside,yellow clay,marked underneath with raised letters ZSC around the top and bottom of the raised number 4406. Marking measures 21/2″x15/8″. Just curious!? Tim