indicated the presence of two peaks in DTG at 180 and between 270[degrees]C and 290[degrees]C corresponding to the decomposition of hydrated calcium hydroxyzincate Ca[Zn.sub.2][(OH).sub.6] x 2[H.sub.2]O and hydrozincite
Large and massive precipitates of hydrozincite
([Zn.sub.5][(C[O.sub.3]).sub.2][(OH).sub.6]) have been formed by a number of loosely bonded nanoparticles (Figure 3(e)).
Linear combination fitting of the XANES and XAFS region of the absorption spectra showed that the speciation of Zn for the hotspot at the edge of the pore and further into the soil matrix chosen in the intact samples was very similar and in forms resembling hydrozincite
, Zn-sulfate, and willemite (Table 3, Fig.
, probably as small encrustations, has been noted from San Carlos (Panczner, 1987).
The matrix pieces, from 5 to 18 cm across, show open cavities lined by crude pale green crystals of tarbuttite covered by carpets of white, acicular, glistening microcrystals of skorpionite, with white crusty areas of hydrozincite
and sparse microcrystals of scholzite.
The natural color of this tarbuttite is a pretty, translucent apple-green, but in the Bahmanns' specimens the sheaves are uniformly coated by opaque, chalky white hydrozincite
. We now await specimens showing uncoated tarbuttite, which could be quite beautiful.
Zinc carbonates such as smithsonite and hydrozincite
have not yet been identified, and aurichalcite has been found sporadically.
Bariand also displayed some outstanding minerals from Iran including red wulfenite crystals, hydrozincite
, orpiment, caledonite and murdochite.
Associated minerals are: hydrozincite
A search through the recently computerized X-ray film archive (9-cm Debye-Scherrer camera) at the Mineralogical-Geological Museum in Oslo verifies that antigorite, clinozoisite, hematite, hornblende, hydrozincite
, lollingite, nontronite, orthochrysotile, portlandite, and stevensite have also been identified from mines and prospects in the Kongsberg area.