I learned that in France, Protestants–particularly Protestant women–can be identified by their wearing the Huguenot Cross. The Huguenots (the origins of the name are uncertain) were French followers of the Reformation. Sometimes they thrived, but other times they endured horrible persecution. In the St. Bartholomew’s Day Massacre (August 24-October 3, 1572), as many as 25,000 were slaughtered. At any rate, this legacy has given them a certain defiant attitude. In Strasbourg, which has a strong Protestant heritage to this day, both Reformed and Lutheran, I noticed waitresses in cafes and others wearing this cross:

As it was explained to me, the cross is Trinitarian. The circle represents the Father; the cross represents the Son; and the dove is the Holy Spirit proceeding from the Father and the Son. It exists in different versions, with the French fleur de lis, as here, hearts, etc. The cross itself is a Maltese Cross, which is the sign of the order of the Hospitillers, the Knights of Malta written about by Bo Giertz in the novel “The Knights of Rhodes” translated by our Bror Erickson. (He’s got a new edition coming out! More on that later!) The reason is that the original patron of the Hugeuenots, King Henry IV, had a connection to that order. I was told that it points to not just the crusading of that order but of their opening hospitals, and so it symbolizes works of mercy. Actual Huguenots followed the theology of their fellow Frenchman Jean Calvin, but I saw Lutherans also wearing this cross.
At any rate, it’s a cool piece of jewelry. I got my wife one.