Two of my favorite IMDb trivia entries are from Congo:
- The "diamonds" used for the scenes during the climax of the movie were actually Herkimer Diamonds borrowed from the Herkimer Diamond Mines of Middleville, New York. They are doubly-terminated (two-ended) quartz crystals that are found in only two places in the world. They were the only gems that would look enough like diamonds and be that large.
- The diamond that was thrown out of the balloon at the end of the movie was lost, and so could not be returned to Herkimer Diamond Mines.
At least the sacrifice was made in support of a worthy movie.