The stone skeleton can take various forms. It is a branched species, sometimes resembling a tree and forming shrubbery that form tangled colonies with leveled upper surfaces. Often the entire colony develops horizontally and does not have a thickness of more than 5 cm. The growth habit largely depends on where the coral grows in relation to tidal levels. Polyps protrude from small cup-shaped depressions called corallites. The color of this coral varies from blue to various shades of brown, often with pale blue tips to the branches.