02/05/2026
We have plenty of rudists in the north Texas area. We find large individual Durania in the Austin Chalk and Ozan Marl. And the Edwards Limestone, the equivalent to the Goodland Limestone to the southwest, is full of Caprinids and other rudists. They sll have very thick shells, and are often recrystalized and the chamber filled with large calcite crystals. Here is what that looks like in thin section. Under crossed polarized light, which makes the beautiful colors.
As you may know I love crystalline rocks, but sometimes I also work with sedimentary ones.
And they contain small treasures, too!
Like this small Rudist in the "Pietra di Aurisina".
Width 5 mm.