| coronadite | |
| Category: | hydroxides |
| Formula: | Pb(Mn4+6Mn3+2)O16 |
| Imasymbol: | Cor[1] |
| Molweight: | 933.55 |
| Strunz: | 4/D.08-70 |
| Dana: | 7.9.1.4 |
| System: | monoclinic |
| Symmetry: | I2/m |
| Unit Cell: | a = 9.938, b = 2.8678, c = 9.834, Z = 1; β = 90.39° V = 280.26 |
| Colour: | dark grey to black |
| Habit: | botryoidal; fibrous |
| Mohs: | 4.5–5 |
| Luster: | submetallic |
| Streak: | brownish black |
| Diaphaneity: | opaque |
| Density: | 5.44 |
| Refractive: | 2.72? |
| Pleochroism: | brown-grey |
| Impurities: | Fe, Al |
Coronadite is the lead endmember of the hollandite group, a family of tectomanganates with a 2 × 2 tunnel structure. The mineral was named after Francisco Vasquez de Coronado who was an explorer of southwest US. The name was made up by Waldemar Lindgren in 1905.[2]