The Royal Cornwall Museum's Rashleigh Gallery houses the mineral collection made by Philip Rashleigh (1729-1811). Rashleigh lived at Menabilly, near Fowey where he was MP, and collected more than 3,000 mineral specimens which he recorded in his manuscript catalogue.

As well as minerals collected by Rashleigh, this gallery contains other mineral collections, a fossil collection with around 2.000 items and a petrology (rock) collection. The large white crystal in the pyramid-shaped case at the centre of the room is Calcite, from Wheal Wrey near Liskeard.

The beautiful exhibition cases were made in 1905 and were restored in February 2007.

The clock standing against the wall to the left of the entrance is from Levant mine, the brass plate next to it is from Dolcoath mine, Cambourne. Dolcoath opened in 1731 and by 1815 was the most important copper mine in Cornwall. By 1840 the copper was almost worked out and tin begain to be mined at deeper levels. Dolcoath then became the deepest mine in Cornwall at more than 550 fathoms (1,000 metres) below adit on the main lode.