ralstonite


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ralstonite

[′rȯl·stə‚nīt]
(mineralogy)
NaMgAl5F12(OH)6·3H2O A colorless, white, or yellowish mineral composed of hydrous basic sodium magnesium aluminum fluoride, occurring in octahedral crystals.
References in periodicals archive ?
The Zapot pegmatite represents the third known occurrence of the alumino-fluoride minerals cryolite, elpasolite, pachnolite, prosopite, and ralstonite in North America.
Minerals in the younger, secondary stage include: fluorite, pachnolite, prosopite, ralstonite, thomsenolite, and weberite.
Small amounts of ralstonite were found associated with other secondary alumino fluorides replacing and veining primary alumino-fluorides.
The paragenetic sequence of secondary aluminum fluorides observed in the pocket is: cryolite to elpasolite and chiolite, followed by thomsenolite, pachnolite and finally ralstonite.
The Morefield elpasolite is associated with prosopite, cryolite, chiolite, thomsenolite, pachnolite and ralstonite.
Other occurrences of elpasolite have been reported from the Cetine antimony mine in Tuscany, Italy (Sabelli, 1987), where it is found sparingly with ralstonite, and from the aluminum fluoride pegmatites of Ivigtut, Greenland (Petersen and Secher, 1993).
Crystals of ralstonite from the Morefield pegmatite are white and translucent.