Here’s a nice example of the Christian symbol of a cross inside a crown. In cemetery symbolism this is thought to represent suffering (the cross) followed by eternal reward (the crown).
The Knights Templar version of this symbol is sometimes set within a Maltese cross. Or you will find it near other Masonic symbols. For more information on the Knights Templar version and its connection to Freemasonry click on the Knights Templar category over on the right side.
Photo: from the headstone of John R. Champion (1856-1917) and Jane L. Champion (1859-1952), Fairmount Cemetery, Denver, Colorado