There was an amazing number of embroidery materials available in the 19th century. Amongst the wide variety were fish scales, feathers, beads, dried husks of larva cases and my favourite, iridescent beetle wings from India.
Over the past fifteen years of trading I have sold a number of pieces of fish scale embroidery and a couple of beetle wing embroideries. I had never before found any old unused beetle wings, until a couple of days ago. They are amazing. Very brittle and a dark brown on the reverse side. They were sold as above and the embroiderer pierces stitching holes in them with a hot needle.
I suppose some would say that they not PC these days and Jui Gabriel in his book on 'Victoriana' describes this kind of embroidery unsophisticated but I would disagree.
See this site for very impressive work -