Complex sentence: Inverell is known as the "Sapphire City" because of the sapphires that found throughout the local district, contributing to a major part of Australia's sapphire production.
Split into simpler sentences: Inverell is known as the "Sapphire City" because of the sapphires that found throughout the local district. The area is recognised for its sapphires, contributing to a major part of Australia's sapphire production.