The Hidden Temple

Wikipedia page for the book says that in the book, they they suggest that they bred the apes to be like more aggressive by breeding them with chimpanzees and humans. So I don't know. That might be one Wikipedia pervert that just snuck that in. And yet the diamonds specifically for that scene were actually real. They were borrowed from the Herkimer diamond mines in Middleville, New York. As a tribute, they put Tim Curry's character in the movie and named him Herkimer based now.