Great grandma's gallstones! In April 1974, my great grandmother, Magdalena Haefner Eck had surgery to remove her gallstones. Dr. Ratke was her doctor. Originally the stones were preserved in formaldehyde, but my aunt dumped it out and just kept the stones (and what appears to be a gross slick of formaldehyde at the bottom of the jar). What a wonderful present from your grandma! I wonder if she wrapped it up.