I dont know that the first marble that I posted is cac was told it was that is what I'm trying to figure out just put it up as a example if it not why is it not? The example that Istmmrbls put up are obvious cacs that not what I'm talking about. I'm trying to find out all the points in identifing plain transparent color on white bases and what they are? So all cac transparent colors have bubbles and that the only way that they are Identified as cac? does it have to do with the size? Have these pic from another thread and this one marble from ebay and just want to learn how to Id them.