This style of stiletto was very popular in the early 19th century when delicate silk bags were used to store needlework projects and tools. The handle also serves as a sheath to protect the point. It unscrews, reverses, and then screws back into the handle for use.
The ivory has turned carving and everything screws together well. It's in excellent condition with no chips, loss or other damage. It measures 2 5/8" long closed and 3 3/8" open and was bought in England. It has a very nice glossy patina.