quartz crinoids in rock

The quartz is somewhat transparent once wet.

horn coral fragment in pebble

There may be a center point towards the tip of the pebble.  You can see an indentation and then several concentric circles.

tapered crinoid bit

Bryozoan sandwich

Here's a pebble filled with several layers of bryozoan fans.  It's fractured apart like a Nutty Buddy bar.  You can make out the dotted edges of unexposed interior fans along the side of the pebble.

mold of crinoid fragment in pebble