Could it be an opal Coprolite?

[Vopros]

This opal is from Lightning Ridge, Australia. Could it be a coprolite

Thanks!

[Carl]

There are several items in there that most researchers agree are not coprolites. And the opal piece has no real features that could be used to determine that it's a coprolite.

[Vopros]

1 hour ago, Carl said:

There are several items in there that most researchers agree are not coprolites. And the opal piece has no real features that could be used to determine that it's a coprolite.

Thank you,  Carl! However this shark Coprolite looks somewhat similar to the opal one

 

[Carl]

"Somewhat similar" is a poor way to ID coprolites. Since their form is so inherently variable, almost anything can look like a turd. For a confident coprolite ID, the specimen should be phosphatic (the opal one can't be) and should have convincing biological inclusions (the opal one does not).