corundum, sapphire, inclusions.5, gems

A brief note by David Brewster reporting a large fluid-filled cavity observed in a specimen of sapphire. The paper extends his earlier investigations of fluids enclosed within minerals and records the presence and behavior of the trapped liquid in corundum. Of particular gemological importance, it is an early specific description of a fluid inclusion in sapphire, demonstrating that such inclusions occur in precious stones as well as in other minerals. The notice forms part of Brewster’s pioneering work on mineral inclusions and the physical conditions under which crystals form.