Moss Rock Boulders are some of the most popular accent pieces of modern design within the United States. They come in a vast amount of sizes and shapes and may have varying amounts of moss already on them. We have a wide variety of many different colors and are medium brown and have reddish accents. That moss rock says it is some of the most popular natural stone on the market today. They can be used for edging along walkways, driveways, and used along with retaining wall stone.