Beautiful, very old English Stone China platter, Willow pattern in blue and white. Backstamp dates this to the 1850s, almost 175 years old. Mark is William Emberton, who worked in Stoke on Trent potteries from the 1840s through the 1860s.
This piece measures 15 3/4" long over the rim, it's large and heavy. This has no chips, cracks or glaze loss, though it's crazed and discolored from age and use.