How far down to find olivine?

Olivine is typically found in the Earth's upper mantle, which lies beneath the crust, starting at depths of about 20 to 30 kilometers (12 to 19 miles) and extending down to approximately 400 kilometers (250 miles). It can also be found in some volcanic rocks and meteorites. In geological formations, the presence and extraction depth of olivine can vary based on specific local geology.