Three symbolic objects are Eilert's manuscript, Thea's hair, and the pistols.
Eilert's manuscript is symbolically the child born of his and Thea's love for each other. In destroying it, Hedda, out of jealousy, seeks to break the bond between the two. Thea's beautiful, abundant hair, in contrast to Hedda's hair, stands for those qualities of captivating femininity Thea possesses and Hedda lacks. The pistols represent masculinity. The fact that Hedda is interested in them is arguably symbolic of the hardening of her character due to her repressed femininity, and in a larger sense might signify the freedom denied women of her time.
Hair is also a symbol of fertility or fecundity. This is also linked to the dichotomy of the characters of Hedda and Thea. Hedda is ironically fertile physically as evidenced in her pregnancy, but sterile in her desire to destory new life, which is symbolised through the burning of Ejlert and Thea's "child". Thea is physically sterile, having only step children.