Q: We have a vase that may be a rare piece of Grueby Pottery. We looked at books on Grueby and the monogram mark is not listed. I was wondering if you can point us in the right direction to further investigate this piece.

A: This script lower case “a” mark was once thought to be used by Addison LeBoutillier, an architect and artist who was also a designer for Grueby from 1901 to 1906. But more recent books questions this, and no one has identified this mark. It may indicate the type of clay, glaze, or shape or other internal pottery information. LeBoutillier is known for his Grueby tiles. The round Grueby Faience Company mark on your vase was used from before 1899 to about 1909. The lack of decoration means that this was not one of the more expensive pieces.