Came by this the other day in San Mateo Ca., what do you think ? The first picture of this ? is not wash the other pictures i wash this ? whatever it is. The last 3 pictures are of the Crack opening where it's been chip open, you can see there a picture with the chip opening. I use a Microscope on last 4 pictures. Me i think it's a Fossil of something . So if someone can tell me what they think or point me to a place i get it look at . Thank you.