Qualitative XRD analysis led to identifying a variety of zeolite species, including analcime, as the dominant zeolytic phase, followed by chabazite, natrolite, thomsonite, wairakite, stilbite
-Ca, phillip-site and stellerite-Na, thomsonite-Ca, chabazite-Ca and chabazite-Na, with minor stellerite, laumontite, levyne, phillipsite-Na, and gyrolite Other secondary minerals associated with zeolites were celadonite (Fe-rich mica), nontronite (Fe-rich smectite), greigeite (iron sulide mineral), koninckite or bobierrite (phosphates), alunite (sulphate), truscottite (silicate), calcite or dolomite, and quartz Nontronite occurred in most samples.
Shortly thereafter, the group found a large zone rich in minerals including laumontite, stilbite
, quartz, heulandite and (the most spectacular of them all) calcite.
Stellerite was identified only by XRD and chemical analysis, but in hand specimen resembles stilbite
com) and a few Indian dealers for exquisitely complete, gleaming milky white "bowties" of stilbite
, 4 or 5 cm long, from Aurangabad?
These veins are typically filled with calcite, infrequently associated with stilbite
Another granite pegmatite region, that of Strzegom-Sobotka (formerly "Striegau"), Silesia, Poland, has produced good specimens of octahedral pink fluorite in crystals exceptionally to 15 cm on edge, associated with good crystals of quartz, microcline, albite, stilbite
and chabazite (Praszkier and Siuda, 2008).
A few of the matrix specimens show associations of quartz, calcite and stilbite
Some "flowers" came out loose; others have small crystals of heulandite, stilbite
, analcime or calcite attached to their bases.
The common zeolites, including heulandite and stilbite
, are calcium-dominated minerals that are fairly high in silica.
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).
It has also produced (as mentioned) brown opaque andradite garnets, globular prehnite, colorless and transparent apophyllite-(KF), stilbite
, stellerite, chabazite-Ca, dark vesuvianite in acicular crystals, zoisite (as the pink variety "thulite"), albite, clinochlore, antigorite, nephrite, chrysotile, rutile, galena, pyrite, magnetite, chromite, diopside, aragonite, fine yellow calcite and quartz (andradite, calcite and quartz are very rare at the famous Jeffrey mine at Asbestos).
5 cm associated with chalky white calcite and 5-mm crystals of brownish stilbite