Are y'all's echinoids calcified?

[Lone Hunter]

Feel like a duh moment maybe coming, I just realized at least some of my irregular echinoids are calcified.  Is this common in Texas? Has anyone sliced one? I'm really curious what they look like naked and thinking of tumbling these ugly ones just to see. Are the structures I'm seeing in the calcite actually part of the echinoid or mineral inclusions?

Edited January 2 by Lone Hunter

[JamieLynn]

 

Some TX formations seem to preserve irregular echinoids with that calcite replacement - here is one of my favorites from the Walnut formation. You can definitely see the structure of the plates.

I don't know what they would look like sliced, but if tumbled, they will lose any detail.