This is a large rock with many prominent quartz veins. These veins are created when minerals in a liquid solution slowly fill cracks and voids in a host rock. This process can take thousands of years and then the replacement minerals harden and become a part of the host. This stone has a very rounded and smooth shape, so it must have experienced tumbling action in a water environment at some point in it's history. It measures approx. 3.5 inches x 2 inches at it's widest points. It weighs 231 grams (about one-half pound).
Refer to the photos. The black centimeter cube is shown for scale and is not included. You get the rock specimen shown.