I believe your lamp shade is made of what is called Capiz Shells - Capiz is a province of the Philippines located in the Western Visayas region.Capiz is known for its mother-of-pearl shells that have the same name and are used for decoration, making lampshades, trays, wind chimes, etc.. I live on the east coast and if you go into any little mom & pop shop on the cape or islands you will find these wind chimes for sale. Really pretty, very thin and curved they use dye to sometimes get a wide range of colors. This is an example for sale on ebay item # 280428097534 Hope this helps.