This is a wonderfully patterned stone known as Wave Dolomite, Rolling Hills Dolomite, or Desert Sandstorm . This stone was discovered years earlier in a small pocket in Mexico and another small pocket has now been found again. It is a stone that is in high demand.
Dolomite is a sedimentary carbonate rock and is found all over the world. Dolomite is both a mineral and a rock. The mineral is the pure form, and Dolomite rock is composed mostly of Dolomite but also with impurities such as Calcite, Quartz, and Feldspar. It is named for the French mineralogist, Deodat de Dolomieu.
It's good for those interested in collecting the many forms of Agate, Jasper, or sometimes other minerals. Although this is a cab, you can also glue on "bails", or have the piece drilled to accept a pinch bail. Either approach will let you turn this sample into a fine pendant.