In the scene where John Hammond is looking at the top of his cane, you see it is made out of one of those pieces of amber with the mosquito inside. What you can also see, when they do the close-up of the amber, is the line where they stuck the two halves together! While Hammond is turning it slowly, watch for the way it catches the light down the middle, showing the seam.

("No insects were harmed in the making of this film"!)