In general a sweetheart brooch was given by a serviceman to his sweetheart before going off to war. Most were high quality and expensive.

My mother has one in the shape of an RAF officer's capbadge. It is made of silver gilt and the wings are covered in small diamonds. The 'gems' in the crown are ruby, emerald and sapphire. The whole thing is no more than 1 1/2 inches across.

The idea was that the sweetheart had something to remember him by, while he was gone and if he didn't come back.

My mother's falls into the latter category.

I believe that it was originally a French idea from the 1800s. They used to cut off one of their embossed buttons from their uniform and give it to their sweetheart. I might be totally wrong about that.

Regards

Chas