Originally Posted by AZ
SURE!
All live sand from the ocean is made from corals. Crushed up by waves fish or other natural things, even man.
I thought the chief constituent of sand was silica (SiO2), aka quartz, which lacks clear cleavage planes and is therefore less prone to fracture, and which is also relatively more chemically stable and less soluble in water than other minerals. I believe that over time coral and other less hard/more soluble minerals break down into ever smaller particles, whereas quartz--being more resistant to breakdown--remains more intact. It's true that Calcium Carbonate (CaCO3) is also another major constituent of sand in temperate ocean regions, but I dont think it's right that "all live sand from the ocean" is made from corals. I think it's pretty much normal ocean sand (SiO2, CaCO3, and other constituents), and the "live" refers to the fact that it's full of various microscopic organisms.
Originally Posted by AZ
Not if it is live rock. Live rock grows it is alive. same as live corals. They add to their skeletons.
I also thought "live rock" wasn't actually alive and growing but was typically made up of dead/fossilized coral rubble and referred to as "live" because it was so encrusted with living things. From about.com: "When talking about live rock (LR), it is a misconception that the rock itself is alive. What makes it live are the many forms of micro and macroscopic marine life that live on and inside of it. The rock itself is only made up of the calcium carbonate skeletons of long dead corals, or other calcareous organisms."