Approximately 7/8 inch, NBS medium. Good condition.
Heath Ceramics is a Sausalito, California company started in 1949 by Edith Heath. They were primarily known for their dinnerware but also made buttons as “kiln fillers“. Button production ceased many years ago. Edith died in 2005 at the age of 94. I was fortunate to be able to purchase a quantity of buttons from her estate. There is an article on Heath in the Winter 2012 California Button Brief that I will be happy to share with you.