Grass Flower stones are naturally formed siltstone dating back to the Paleozoic era that ranged from 250 to 500 million years ago. As the name implies, siltstone is a sedimentary rock that is composed of tiny rock and mineral particles that are difficult to see. Silt particles are larger than clay but smaller than sand particles. Silt is carried by water, wind, and ice and is deposited, often in enormous quantities. Under time and pressure siltstone is transformed in rock. In the process, cracks, fissures, and pores develop that may eventually be filled with minerals such as iron oxides, manganese, and others. These additives are responsible for the interesting patterns and colors in these stones. The stone is mined in large blocks and then cut into different shapes—round, oval, and rectangular being the most common. These are then ground smooth and given a coating of varnish or a comparable treatment to make them shiny and make the colors stand out.

The stone is mined in Liuzhou County in Guangxi Zhuang Autonomous Region in South Central China. Liuzhou was one of the main centers for the development of modern Chinese stone appreciation and many fine types of stone came from the Liuzhou region. In the mid- to late-1990s, the siltstone from which Grass Flowers were created was discovered. This was a time when many other stone types were being found and introduced into the rapidly growing stone markets in China. This stone was originally abundant and easy to work, and as a consequence hundreds of thousands of Grass Flower stones were produced. These served as a low-cost entry-level stones for petraphiles in China and abroad. There are indications that the original source of these stones may soon be depleted. This will result in fewer stones coming into the marketplace and an increase in prices.