Craft Lodge Officer Past Master Breast Jewel

The jewel representing the 47th Problem of Euclid in Freemasonry symbolizes the knowledge and progress gained by someone who has served as the Master of the Lodge. 

Euclid, a renowned mathematician from ancient Alexandria (around 260–320 B.C.), authored a collection of thirteen books known as "Elements." These books contained 465 mathematical problems, and the 47th problem is famously known as the Pythagorean Theorem. The theorem, which states that in a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides, represents wisdom, learning, and the application of knowledge—key values in Freemasonry.