This is a large Scottish sterling silver plaid pin made in 1947 by Thomas Kerr Ebbutt of Edinburgh.  The pin has a large stone set in its centre and is engraved with Scottish motifs.  The stone is some type of quartz, maybe a citrine or a Cairngorm stone.  The pin measures 3 1/4” in diameter and weighs 3.2 oz.  It is fully hallmarked on the back.

This is a gorgeous plaid pin that could be worn as a brooch - super quality and unusual large size, this is a real beauty!