Pit Firing Process
Generally speaking, pottery that is referred to as being Pit Fired is not glazed. It has been fired in an open bon-fire or primitive pit kiln. When these burnished pots come into direct contact with sawdust, carbon trapping may occur, creating a deep black color.
Copper is added to the Pit before stacking wood over the pots. As the firing progresses the copper vaporizes and flames fume the pieces with gaseous patterns of red, blue, green and yellow. After firing hot wax is used to seal the surface and enhance the colors.
Pit fired Vessels are not water tight. If you want to put flowers in the vase use only dry or silk flowers.