Properties
No property table for this entry: the article it resolves to has no infobox, so Mohs hardness, crystal system and the other properties are not available. Nothing has been estimated or added.
From the Wikipedia article
Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.
Source
Source record: crystal-compendium/coral/minerals.json. Fetched from English Wikipedia by the operator 2 October 2026.
https://en.wikipedia.org/wiki/Coral — revision id 1375048390. Text and properties from Wikipedia, licensed CC BY-SA 4.0.