Haiweeite 
Ca(UO2)2Si5O12(OH)2 • 3H2O [CNMNC approved formula]
Named after it's locality: Haiwee Reservoir, Inyo County, California, USA.
| IMA status : | Approved Species 1959 () |
| CLASSIFICATION | |
| Dana (8th edition) : |
53.03.02.02 |
| (53) Nesosilicate Insular SiO4 Groups and Other Anions of Complex Cations | |
| (53.03) with (UO2) | |
| (53.03.02) Weeksite group | |
| Nickel-Strunz (10th edition) : |
09.AK.25 |
| (09) Silicates | |
| (09.A) Nesosilicates (Isolated tetrahedron) structures | |
| (09.AK) Uranyl neso- and polysilicates | |
| Crystal system: | Orthorhombic System |
| Point group (H-M): | mmm (or 2/m 2/m 2/m) — dipyramidal |
| Other Properties: | Radioactive. |
| Comments: | Radioactive. |