Mica Bonsai pots imported from Korea are made of 80% mica, 15% polyethelene and 5% graphite. Mica has a natural ability to stabilize the temperature of the soil in the pots. This promotes healthy root activity during the growing season and protects during the cold periods. These pots are extremely durable and will withstand the elements for years. The pot has a wide lip and is dark brown in color.