This is a Mexican sterling silver combination brooch or pendant with a large dark stone I believe might be some type of fossilized stone or wood. The brooch is signed TAXCO MEXICO, 925 and CASTANEDA. It also has an Eagle 3 mark. I do not know what type of stone is in the brooch but it has a glow to it in the light and the striations show up. The brooch measures 2-1/4 inches by 2 inches. The stone is 1/4 of an inch thick. The brooch weighs 28.5 grams. The stone is in good condition and any spots that appear in my pictures are simply reflections. The brooch is in very good condition but does have an age patina and may need cleaning or polishing. Please let me know if you have any questions. Thanks for stopping by.