Final answer:
Diamond mines where most of the world's diamonds come from are located in South Africa, Botswana, Namibia, and Canada, with notable operations by DeBeers.
Step-by-step explanation:
The majority of the world's diamonds come from diamond mines located in various countries. One notable company that controls a significant portion of global diamond production is DeBeers. They have mining and production operations in South Africa, Botswana, Namibia, and Canada. These countries have abundant diamond deposits and contribute to the majority of the world's diamond supply. For example, diamond mining is found in parts of Botswana and along the coast of Namibia.