Our mushrooms are made of FiberStone, a mixture of sand and stones reinforced with a fiberglass backing. The surface is then sandblasted and treated to create the moss finish. Variations in color will occur. Made in the USA, the mushrooms may be left outdoors indefinitely. Small: 6.25" DIA. x 8”H; 2 lbs. Medium: 9.75”DIA. x 10”H; 4.5 lbs. Please note: Each item is made to order. The artisan workshop does not maintain inventory and is the last facility in the USA making fiberglass garden ornaments and containers. Your order keeps jobs in the USA, but we estimate fulfillment will take up to four weeks, and sometimes longer. Hence, it is not recommended that you order if you require delivery in less time. We are unable to expedite these products, even under special circumstances.