Grimselite 
K3Na(UO2)(CO3)3 • H2O [CNMNC approved formula]
Named for the locality: Gerstenegg (Kabelstollen Gerstenegg-Grimsel I), Grimsel, Bern, Switzerland.
| IMA status : | Approved Species 1972 () |
| CLASSIFICATION | |
| Dana (8th edition) : |
15.02.06.01 |
| (15) Hydrated Carbonates | |
| (15.02) where A+m B++n (XO3)p · x(H2O), (m+n):p > 1:1 | |
| (15.02.06) | |
| Nickel-Strunz (10th edition) : |
05.ED.35 |
| (05) Carbonates and Nitrates | |
| (05.E) Uranyl Carbonates | |
| (05.ED) UO2:CO3 = 1:3 | |
| Crystal system: | Hexagonal System |
| Point group (H-M): | 6m2 (or 6m2) — ditrigonal-dipyramidal |
| Other Properties: | Radioactive. H2O Soluble. |
| Comments: | Radioactive. |