I dont think I even need to post a picture, because I find so many I think you've probably come across them before. The small (1in-.25in) round thin disks that look like a vinyl that sat in the sun, they often have a ripple in them, some more pronounced than others. THey lack much pattern other than a minutely pitted surface. Most of the time I find them alone, not stuck to any kind of matrix, sometimes I find chunks of rock full of them. what the heck are they? CFL area of course. so Im assuming marine.