This set is made of natural Nautilus Fossils. These 3 Ammonites are encased in sterling silver frames. all are engraved with the sterling Hallmark, .925, on the backs. The earrings have sterling silver, thick, bead edged frames with fish hook style, pierced findings. The set is in beautiful condition. The pendant measures 2-3/4" x 1" wide, and each of the matching earrings are 1-1/4" x 3/4 inches wide. Gorgeous! This is as close to being a perfect set as I've ever seen. They are over 4 million years old, but look brand new! Ammonites are the fossilized, hard shells of extinct mollusks. Their closest relative is the chambered Nautilus from the Pacific and Indian oceans. Ammonites were named after the Egyptian god, Ammon who was said to possess the head of a ram which is similar in shape to these ancient mollusks. Ammonites appeared 400 million years ago and became extinct with the dinosaurs approximately 65 million years ago. Much like the nautilus shell, you can clearly see the chambers on these ammonite slices. Many civilizations have history using the ammonite. The Navajo carried ammonite as a fetish for good hunting and good fishing. Ancient used ammonite for medicinal purposes. Because the shape resembled coiled snakes, the English and Scots thought they could cure snake bites.