| Fiorite | |
| Category: | Mineraloid |
| Formula: | SiO2·nH2O |
| Habit: | Globular, botryoidal, or stalactic |
| Fracture: | Conchoidal |
| Luster: | Pearly |
Fiorite is a hydrated silica mineraloid, a form of opal, found in cavities in volcanic tuff. It is a globular, botryoidal, or stalactic concretionary form of opal. The mineraloid has a pearly lustre and forms botryoidal masses. Named after Santa Fiora, Italy, fiorite is used as a gemstone.[1]