Antique ladies' fans often incorporate bone or ivory into their slats. Whether the fan is made of bone or ivory will affect the fan's value. Close observation and a few simple tests can help you determine what the fan is made of.
Examine the lady's fan with the magnifying glass. Make sure the lighting in the room is bright enough that you can see the details of the bone or ivory portion of the fan. A shiny texture points to ivory. If it has a matt texture, the fan is most likely made of bone.
Examine the fan again with the magnifying glass. Tiny black or brown pores in the fan's slats means that it is made of bone. The pores are traces of where blood vessels once were. If instead of pores, you see lines running vertically down the fan's slats, it is made of ivory.
Put on a leather glove to protect your hand. Heat the pin by holding the tip against a hot stove burner. Once the pin is quite hot, place the tip against one of the fan's slats, preferably in an area that is not readily visible. If the hot pin causes the slat to smoke, it is made of bone. If it does not smoke, the fan is made of ivory.
Use the pin to lightly scratch the surface of one of the fan's slats, again choosing an area that is not readily visible. If you are able to create a scratch easily, the material is most likely bone. It will prove much more difficult to scratch ivory.
Step 4 should be done carefully so as to avoid extensively scratching the fan and thereby reducing its value. If you are able to positively identify the fan's material with Steps 1, 2 and 3, Step 4 may not be necessary.