This is an antique, light brown or tan, glazed ceramic door knob likely dating from the 1800s to early 1900s.  The round ceramic knob was likely handmade from local clay and contains no hardware.  The vintage doorknob was on a door in an old plantation home in Virginia that dates somewhere between 1795 and 1835.  I don't know if the knob was original from when the house was built or added at some point in time prior to 1953 when my grandparents purchased the property.  The knob was chipped and replaced after that time.  The chip is about dime sized on one edge and you can see the red color from the original clay in the break. (See photos).  From what I've read, this style of knob was popular from the 1850s to the early 1900s. The vintage knob measures about 2" round x .75 tall.  It is sold as is.