| Blödite | |
| Category: | Sulfate minerals |
| Formula: | Na2Mg(SO4)2·4H2O |
| Imasymbol: | Blö[1] |
| Strunz: | 7.CC.50 |
| System: | Monoclinic |
| Class: | Prismatic (2/m) (same H-M symbol) |
| Symmetry: | P21/a |
| Unit Cell: | a = 11.04 Å, b = 8.15 Å, c = 5.49 Å; β = 100.41°; Z = 2 |
| Color: | Colorless, yellow, may be dark gray, bluish green, or reddish due to inclusions |
| Habit: | Prismatic to equant crystals, granular, massive |
| Fracture: | Conchoidal |
| Tenacity: | Brittle |
| Mohs: | 2.5–3 |
| Luster: | Vitreous |
| Refractive: | nα = 1.483, nβ = 1.486, nγ = 1.487 |
| Opticalprop: | Biaxial (−) |
| Birefringence: | δ = 0.004 |
| 2V: | 71° (measured) |
| Gravity: | 2.23 |
| References: | [2] [3] [4] |
Blödite or bloedite is a hydrated sodium magnesium sulfate mineral with the formula Na2Mg(SO4)2·4H2O. The mineral is clear to yellow in color often darkened by inclusions and forms monoclinic crystals.
Blödite was first described in 1821 for an occurrence in a salt deposit in Ischler Salzberg, Bad Ischl, Gmunden, Austria and named for German mineralogist and chemist Karl August Blöde (1773–1820).[3] [4]
It is found worldwide in evaporitic sedimentary environments such as the Great Salt Lake, Utah.