Traditional Scottish agate brooch stamped "Sterling Silver" as shown in the photo of the back. It has a large (3/4" diameter) purple glass stone at its center. There are carnelian and bloodstone agates set in etched silver with sterling prongs holding the purple stone in place. Clasp is in excellent condition and all prongs are firm. This is a beautiful example of the Scottish jewelry made popular by Queen Victoria although this piece is probably early 20th century. The pin measures 1 1/2" across.