Interesting rock.  Can you tell us where in Texas you found it?  "Texas" is pretty broad, and its geology varies quite a bit from place to place.  Both the location (at least nearest town) and the kind of place (natural bedrock outcrop, beach or riverbank, road or railroad, mine or quarry (what do they mine there?), construction site, an old rockhound's garage?  Knowing those two things allows us to check the local geology and narrow down the possibilities.  And if you have no idea where it originated, that's o.k., too.

Although this photo came out pretty well, for future reference it usually works best to place the specimen (clean & dry as you have done) on a plain, non-textured white background like a sheet of paper so the camera can focus on the specimen and not the background.  Lighting should be outdoor daylight or equivalent.  The specimen should occupy most of the photo frame.

Can you make a scratch or nick in it with a steel needle or a sharp steel knife point?