Tip of the hat to Christopher Locke for immortalizing these once cutting-edge, but now archaic pieces of technology for future generations. Locke reproduced these pieces out of concrete and "other secret ingredients." What ever he did, it looks like real stone fossils. Best part, you can buy them. Each fossil is made one at a time, by hand, in an individual mold. Because of the hand-made nature of the item, there will be variations in pigmentation, and small imperfections in the surface. You can choose a general color range, but given that each one is handmade (read unique) color variations are inevitable.