I had no idea what it was until they showed me. Still wondering why they use this to attach the rubis to the anchor instead of a "ultra high performance latest technology superglue". It was new to me and still amazed, it was a great find and very interest...
But it still does the trick. the shallac is heated and allows the jewels to set slowly so they are aligned, rather then quick drying glue that can cause the jewels to set slightly off.