Definition: A taxon is Vulnerable when the best available evidence indicates that it meets any of the criteria A to E for Vulnerable, and it is therefore considered to be facing a high risk of extinction in the wild.
Definition: A natural chemical precipitate of carbonate minerals; typically aragonite, but often recrystallized to or primarily calcite; which is deposited from the water of mineral springs (especially hot springs) or streams saturated with calcium carbonate.