Other rarities occurring in the pegmatites of this area include microlite, hambergite and rhodizite
(Antandrokomby is one of the world's richest sources of this mineral).
From Ambalahe, Manapa, near Betafo, come very lustrous, striated, short-prismatic liddicoatite crystals with trigonal terminations, mostly around 3 cm but exceptionally to 12 cm, loose or on pegmatitic matrix; these crystals are a very dark greenish brown to black but have rich red internal highlights, and on a few of their surfaces rest sharp, lustrous, snow-white dodecahedral crystals of londonite (the cesium analog of rhodizite
first described in 2001) to 3 mm.
To add yet further spice, the sprinkling of pale ivory-white sparkling crystals on one side of the "sibirite" spray appears to be the extremely rare rhodizite
, a characteristic associate of sibirite from Shaitansk, which is the co-type locality.
Lino explains that since this material has tested extremely high in rubidium, it may in fact be neither rhodizite
nor londonite but a new species.
At the booth I noticed Erica Pohl, the wonderful collector from Switzerland, looking at a very fine, unusual specimen of rhodizite
The elbaite crystals reach 3 cm individually, and occur in floater groups of toenail to miniature size; what is more, grayish white, translucent dodecahedrons of rhodizite
to 5 mm are sprinkled liberally on their surfaces, for a fetching white-on-black effect.
Another whole shelf was full of large yellow crystals of what used to be called rhodizite
, but is now recognized as the new mineral londonite (the cesium analog of rhodizite
) from Mahaica, Madagascar.
Relationship to other species: It is the Cs-dominant analogue of rhodizite
Londonite, a New Mineral: the Cs-dominant Analog of Rhodizite
The Italians are heavily connected with mining in Madagascar and so numerous large and fine crystals of rhodizite
were available, especially from Lino Caserini, and liddicoatites (some on matrix) from Enio Prato.
According to Skip Simmons, a co-author of the IMA-approved but as yet unpublished formal description (who gave permission for us to mention the name), some of the crystals are rhodizite
and some are londonite; some are white and some are yellow, but color does not correlate with composition.
The Sarapulka and Shaitanka pegmatites are irregular thin veins containing rubellite and rhodizite
in the west and green and blue aquamarines in the east.