This is a vintage Sterling silver Blue Morpho butterfly wing pendant by TLM, Thomas L. Mott, an English jewelry maker during the 1870s, and is known for popularizing natural butterfly wing jewelry. A surge in the demand for butterfly wing jewelry rose in the 1920s after a collection of pieces were shown at the 1924 British Exposition. The piece is stamped TLM Sterling England on the back, and is from the Art Deco period. The pendant is crafted in sterling silver&nb...sp;and features a genuine butterfly wing that is preserved behind glass. The butterfly wing has intense shades of vivid blue color and remarkably strong iridescent properties, causing it to flash brilliantly when turned in the light. The polished glass frame rests within a closed back setting, and is surrounded by a milgrained bezel. The bale has a beautifully made flower decorating the front. The pendant measures 1 3/4 inches long, including the bale, and measures 7/8 inches at its widest point. I will insure this piece for its full value when I ship it. Thanks for looking!