Royal Order of Scotland jewel. Also an element in the 11th and 12th degrees of the Rectified Scottish Rite.
It can also be found on this “Parfait Macon” tracing board in the Kloss collection.
Top: Wikimedia Commons
Bottom: collection (1844) of Georg Kloss (1787-1854) (Collection de 84 tableaux, Kl.MS:XXV.1)