Thomsonite varies in habit showing bladed crystals, spherulites, radial crystal groups and rich coatings mainly made up of small crystals, although it sometimes has a fibrous nature Analcime appears as vitreous and granular well-formed trapezohedral crystals which are often colourless and sometimes white Natrolite is generally beige to white, either massive or forming radiating fibers and shows a more glassy brightness than mesolite
, which is generally milky white and fibrous, having larger fibers than those of natrolite Stilbite commonly occurs as vitreous sheaves or plates, ranging from colourless to green to white
X-ray and Raman analyses by Bob Downs at the Universty of Arizona have just recently shown the material to be mesolite
. In these large-cabinet specimens, pale yellow-brown spherical aggregates of radiating acicular crystals rest, singly and in clusters, on basalt matrix.
Other famous mineralogical locality of zeolites (natrolite, analcime, phillipsite, mesolite
, thomsonite) together with apophyllite, calcite and chlorite was described by Bouska and Malec (1971) in amygdales of a basanite intrusion near Soutesky.
They are "heulandite" (heulandite sensu stricto and clinoptilolite), chabazite, analcime, stilbite, barrerite, epistilbite, gmelinite, laumontite, natrolite, mesolite
, scolecite, stellerite, tetranatrolite, thomsonite, and wairakite.
Back in the pavilion, case after wide case held wonderful specimens of Deccan Plateau minerals: a highlight was a mesolite
specimen from near Pune, with great white sprays of acicular crystals covering a matrix plate nearly a meter wide, in one of the several cases put in by K.
[Na.sub.2][Ca.sub.2]([Al.sub.6][Si.sub.9])[O.sub.30] * [8H.sub.2]O
A number of other zeolites have also been reported from Merelani, including laumontite and mesolite
in tufts of acicular white crystals, and stilbite, scolecite and chabazite-(Ca).
Merchant was also one of two major Indian dealers with new specimens of mesolite
on fluorapophyllite--excuse me; apophyllite-(KF)--from the Lonavala quarry near Pune (Poona), where the huge pocket in question was cleaned out in November-December 2007.
Crocoite, scolecite, mesolite
, cerussite--such specimens and other fragile delicacies are highly desired by avid mineral collectors.
The burst of white gemmy needles of mesolite
seems to explode from the green apophyllite crystals below.
The Lonavala quarry has produced fine specimens of green fluorapophyllite, some of the world's finest specimens of mesolite
(after those of the Pashan Hills quarries), and recently some specimens of the beautiful blue vanadium minerals cavansite and pentagonite, formerly known primarily from the Wagholi quarry complex.
The present study was prompted by a serendipitous discovery of well-formed crystals of gismondine, chabazite-Ca and mesolite
in a road cut near Laurel, Quebec, by Canadian Museum of Nature staff in 1983.