The mica is an old stumpwork trick, although I’ve never seen it used in quite that way. It looked like it was split into very thin rectangles, then a hole made at the top to attach. Was the dress fabric linen? My local carries a gorgeous gray linen with a metallic finish that looked very like it.
Terry, that dress was incredible. Question – were you looking at antique fabrics for that design? I have a picture of an old blue silk embroidered with gold metal acorns and ribbons that I thought of as soon as I saw the dress. Although no source that I know of has ever had the brilliant idea of transforming it into a pattern of falling leaves. What a wow moment.