| Rastsvetaevite | |
| Category: | Silicate mineral, Cyclosilicate |
| Imasymbol: | Rtv[1] |
| Strunz: | 9.CO.10 |
| Dana: | 64.1b.1.2 |
| System: | Trigonal |
| Class: | Ditrigonal pyramidal (3m) H-M symbol: (3m) |
| Symmetry: | R3m |
| Unit Cell: | a = 14.25, c = 60.97 [Å] (approximated); Z = 3 |
| Color: | Reddish-pink |
| Habit: | irregular grains |
| Fracture: | Conchoidal |
| Tenacity: | Brittle |
| Mohs: | 5-6 |
| Luster: | Vitreous |
| Streak: | White |
| Diaphaneity: | Transparent |
| Gravity: | 2.86 |
| Opticalprop: | Uniaxial (+) |
| Refractive: | nω = 1.60 nε = 1.60 (approximated) |
Rastsveatevite is a rare mineral of the eudialyte group with the chemical formula . Its structure is modular.[2] It is only the third member of the group after andrianovite and davinciite with essential (site-dominating) potassium. Potassium and sodium enter both N4 and M2 sites.[3] The mineral is named after Russian crystallographer Ramiza K. Rastsvetaeva.[4]
Rastsvetaevite was originally found in hyperagpaitic (ultra-alkaline) pegmatite at Mt. Rasvumchorr, Khibiny massif, Kola Peninsula, Russia. Associated minerals are aegirine, nacaphite, nepheline, natrite, schcherbakovite, sodalite, villiaumite, and rasvumite.
The c unit cell parameter in rastsvetaevite is doubled.