This very cool set of Orthocerus fossil pendants is predrilled (front to back) and ready for stringing into a matched necklace/earring set, or for use separately. The largest stone is approx. 39 x 24 mm., with an approx. 2 mm. hole. The two smaller ones are slightly different in size -- the smallest at approx. 34 x 14 mm., the larger at approx. 40 x 15 mm. The hole in this latter pendant (40 x 15 mm. one) is slightly chipped. Each of the smaller pendants has an approx. 1 mm. hole. Orthoceras ("straight horn") is a genus of a now-extinct nautiloid cephalopod -- a once living, shell like organism. The stones are polished to better reveal their lovely black and grey and off-white hues. The vertebrae structure is clear as shown in the photos. If you'd like more info or photos, or if you'd like to purchase separately or in different combinations, you can always contact us.