Rio Tinto Retrospective brings together the top-judged pieces since 1987 from the Muswellbrook Open Art Prize and Muswellbrook Open Photographic Award.

There are more than 60 pieces on display that take up most of the space inside the gallery.

Works range from prints, ceramics and photographs and represent the past 25 years of sponsorship given by Bengalla Mining Company and Coal and Allied.

Nationally recognised artists such as Rosemary Valadon and her self portrait And All I Wanted, which won in 1987, Angus Nivison with his work Menace, which took out the prize in 2002, and Doug Spowart with three of his award-winning photographs are some of the artists' pieces on display.

Arts centre education officer Roger Skinner said visitors could expect to see some of the best works by fine artists – all in the one space.

“It is a grouping of the collection that hasn’t been seen before,” Mr Skinner said. “All the works have been exhibited before, but this is the first time they have appeared together as a collection.”

The exhibition also features the gallery’s biggest and smallest works together in the one room. The smallest piece is an unfixed gelatin silver print titled Mind Field by Anthony Mravicic, which won the photographic award in 2008. The biggest piece, titled Orange Orchard and River by Peter Atkins, won the art prize in 1991.

Rio Tinto Retrospective will be officially opened and a book on the exhibition launched tonight at an invitation-only cocktail party. It will open to the public tomorrow from 10am and run until February 26.