 It was added to the Queensland Heritage Register on 21 October 1992.The former assay office was constructed in 1899 to process ore samples from the Mt Garnet Freehold Copper and Silver Mine.The copper, silver and zinc lode at Mount Garnet was discovered in 1882 by Albert Vollenweider and Henry Faasch, who, with James McLeod, manager for John Moffat, applied for a selection of in October 1882.