This base rock is fully cured, and is part of the premium rock we receive but does not make the cut to go in our premium live rock pools. They range in all sizes and still have some very nice shapes as well, but the coverage(coraline,algae,etc) on them is usually non existent. They would make excellent base structures for any tank, and gain that coverage within time. Feel free to call us and ask about our many different types of rock and how they look this week! We get in rock weekly so it may change very quickly.