Rastsveatevite is a rare mineral of the
eudialyte group
Eudialyte group is a group of complex trigonal zircono- and, more rarely, titanosilicate minerals with general formula (1)N(2)N(3)N(4)N(5)sub>3 (1a)M(1b)sub>3M(2)3M(4)Z3 i24O72'4X2, where N(1) and N(2) and N(3) and N(5) = Na+ and more rarely H3 ...
with the chemical formula . Its structure is modular. 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.
The mineral is named after Russian crystallographer Ramiza K. Rastsvetaeva.
[Mindat, http://www.mindat.org/min-26586.html]
Occurrence and association
Rastsvetaevite was originally found in hyperagpaitic (ultra-alkaline)
pegmatite
A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than and sometimes greater than . Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic com ...
at Mt. Rasvumchorr,
Khibiny massif
The Khibiny Mountains (russian: Хиби́ны ; sjd, Umptek) is one of the two main mountain ranges of the Kola Peninsula, Russia, within the Arctic Circle, located between Imandra and Umbozero lakes. The range is also known as Khibiny Massif, K ...
, Kola Peninsula, Russia. Associated minerals are
aegirine,
nacaphite,
nepheline
Nepheline, also called nephelite (), is a rock-forming mineral in the feldspathoid groupa silica-undersaturated aluminosilicate, Na3 K Al4 Si4 O16, that occurs in intrusive and volcanic rocks with low silica, and in their associated pegmatites ...
,
natrite,
schcherbakovite,
sodalite
Sodalite ( ) is a tectosilicate mineral with the formula , with royal blue varieties widely used as an wikt:ornamental, ornamental gemstone. Although massive sodalite samples are opaque, crystals are usually transparent to translucent. Sodalite i ...
,
villiaumite
Villiaumite is a rare halide mineral composed of sodium fluoride, Na F. It is very soluble in water and some specimens fluoresce under long and short wave ultraviolet light. It has a Mohs hardness of 2.5 and is usually red, pink, or orange in col ...
, and
rasvumite.
Notes on crystal structure
The ''c'' unit cell parameter in rastsvetaevite is doubled.
References
Cyclosilicates
Sodium minerals
Potassium minerals
Calcium minerals
Iron minerals
Zirconium minerals
Trigonal minerals
Minerals in space group 160
Minerals described in 2003
{{silicate-mineral-stub