Heart pendants in various sizes were commonly worn in the 18th century!  Sometimes they are tiny and sometimes they are quite large, like this filigree pendant.  This piece is made with high-quality cast brass plated in your choice of Gold, Silver or Antique Gold.  These were almost universally worn on narrow black ribbon, but every so often you would see other colors. 

Black silk ribbon available here: 

35x31mm in size. 

See 18th Century images on pendants worn on ribbon here: