Utilize the input text as a context reference, choose the right relationship between Turquoise Hill Resources and gold from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

July 15 (Reuters) - A project financing agreement for the underground expansion of Oyu Tolgoi, a massive copper and gold mine in Mongolia, is expected to be signed by year end, mine owner Rio Tinto (LSE: RIO.L - news ) 's Turquoise Hill Resources (Toronto: IVN.TO - news ) unit said on Wednesday.

Answer: product_or_material_produced