Aragonite is a carbonate mineral that can be white, red, yellow, orange, green, blue or brown. It can grow as columnar crystals or as stalactite crystals that look like branches. Aragonite forms naturally in almost all mollusk shells and as an endoskeleton of corals. It is used in aquariums to replicate reef conditions and help to keeps its PH balance at an almost natural level. Starborn generally uses Moroccan Aragonite, which is orange to orange-brown and is a cluster of several columnar crystals bursting in all directions.