Fossilized Coral

Coral are tunnel like homes built by tiny sea creatures called polyps which consume plankton while also absorbing calcium and carbonate directly from sea water through their skin. These two minerals combine in the polyps body to create calcium carbonate which is then excreted layer by layer and used to build coral as a home

When the polyps die the coral left behind is buried in ocean floor sediment layer by layer over time preserving the coral. In that time dissolved minerals take the place of the coral which is commonly silica forming various shades and varieties of Quartz, Agate, Chalcedony and even sometimes makes Coral Geodes! You will often find different shapes and patterns depending on the species of polyp that made it as well

Hardness: 6.5 – 7
Composition: SiO₂