Band of Gold
Claire has two husbands, but not in a Sister Wives: Scotland Edition (or would that be Brother Husbands?) sort of way. Her first husband, Frank, hasn't even been born yet when Claire marries her second husband, Jamie, in 1743.
Time travel gives us a headache.
Still, even though Claire is permanently separated from Frank, she still loves him. She wears her wedding ring from him alongside the one Jamie gives her, "a wide silver band, decorated in the Highland interlace style, a small and delicate Jacobean thistle bloom carved in the center of each link" (23.151). It's so pretty, you can buy one of your own.
The fact that Claire wears both shows us that she still loves both her husbands, and also that she is connected to two different worlds. Do you think she'll ever take off the ring she got from Frank? Perhaps future books will tell.