Probably part of a necklace. Hollow, and made of two halves. The top is patterned in repousse, and the bottom is tipped with a small pyramidal knob. Acorn is attached to a stem (gold tube) which is fastened to a small hollow bead pierced horizontally for suspension.
Condition: Stem separated form acorn; seam in stem partly open; small bead bent at join with stem; dent in one side of acorn.