The coral paperweight symbolizes Winston's desire to escape into the time before the Party took over. He longs, in an idealized way, to recapture some of what normal life was like in those former days. As Winston thinks when he buys the artifact:
What appealed to him about it was not so much its beauty as the air it seemed to possess of belonging to an age quite different from the present one. The soft, rainwatery glass was not like any glass that he had ever seen.
The coral paperweight also symbolizes the special world that Winston attempts to create with Julia separate from the everyday world of the Party they both must function in. As Winston thinks:
The inexhaustibly interesting thing was not the fragment of coral but the interior of the glass itself. There was such a depth of it, and yet it was almost as transparent as air. It was as though the surface of the glass had been the arch of the sky, enclosing a tiny world with its atmosphere complete. He had the feeling that he could get...
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