Almost impossible many times to tell the difference between a Christensen Moonie and an Akro. There are, however, several traits to look for that can set them apart. Akro Moonies tend to have more of an orange backlit hue, even if the marble appears more blue in hand. They may also be more clear/white in colour compared to the Christensen which can be more blue, however, this isn't always the case. Akro you may find a "fish eye" when backlit, which looks like a round hole illusion. Moonies made by Christensen should have a slightly swirly interior, almost like small bands of waves, or streaks like in a Cloudy blue sky. Another strong indicator in combination with these is being out of round as many Christensens tend to be. Finite creasing/cold folds might also be found This one is a perfect example of all of the above mentioned details. Surface is Mint, has an asmade linear glass crease and is .03" oor (.79"/.76")