Greenstone Resources Corporation (GRC) – Siana Gold Project (SGP), formerly owned by RED 5 Limited and currently a subsidiary of TVI Resource Development Philippines Inc. (TVIRD), operates the Siana Gold Project (SGP). It is positioned as the third gold mining entity and fourth operating mine within the portfolio, following Agata Mining Ventures Inc. (AMVI) and TVIRD's Balabag Gold-Silver Project (BGSP).

Greenstone is a duly registered company engaged in mining and processing both gold and silver and is governed by a Mineral Production Sharing Agreement (MPSA), officially designated as MPSA 1842002-XIII (the "Siana MPSA"), grated on December 11, 2002, and registered with the Mines and Geosciences Bureau Regional Office XIII for 25 years. This agreement is bifurcated into two non-contiguous north and south parcels, encompassing a combined area of 3,288.8 hectares, strategically situated in the municipalities of Alegria, Mainit, Tubod, and Bacuag, in the province of Surigao del Norte. The primary mining operations and development activities are concentrated in the northern block, which aligns with the 715 hectares covered by the Environmental Compliance Certificate (ECC). The communities directly or indirectly affected by the mining operations, encompassing social, economic, political, and environmental dimensions, consist of eight barangays, including five Mamanwa Indigenous Peoples (IP) groups.

Under the stewardship of RED 5 Limited since its acquisition in 2001, GRC has exhibited resilience and commitment in overcoming challenges to secure its social and operating licenses. The SGP commenced gold production in 2012, achieving a noteworthy milestone after constructing the process plant and establishing Tailings Storage Facility (TSF) No. 4. Despite a two-year hiatus from 2013 to 2014, the Project demonstrated resilience and resumed operations. In April 2017, the Project voluntarily ceased operations and underwent care and maintenance, showcasing responsible management. Under the new management of TVIRD, the Project was successfully recommissioned in September 2021, indicating a promising future