Rock sample with two polished surfaces. This is a sample of a metamorphic rock, most likely impure marble or quartzite. Alexander Stewart Herschel had the greatest interest in geology and this piece may have been collected by him.

This sample comes from a 15-drawer cabinet found in the Herschel family home in the 1950s. The contents of this and a similar cabinet seem to suggest that they were used by successive generations of the family to store specimens, material and apparatus for carrying out experiments.