| Nobleite | |
| Category: | Phylloborates |
| Formula: | CaB6O9(OH)2·3H2O |
| Imasymbol: | Nob[1] |
| Strunz: | 6.FC.05 |
| System: | Monoclinic |
| Class: | Prismatic (2/m) (same H-M symbol) |
| Symmetry: | P21/a |
Nobleite is a rare borate mineral with the chemical formula CaB6O9(OH)2·3H2O. It was discovered in 1961, in Death Valley, California, and is named for Levi F. Noble, a USGS geologist, in honor of his contributions to the geology of the Death Valley region.
Nobleite has also been identified at two localities in Chile and Argentina.