The vast collection of minerals--smooth turquoise smithsonite from New Mexico, spiky orange
crocoite from Tasmania, dazzling purple amethyst from Uruguay, and large specimens of sulfur from Sicily--are recommended for a viewing at the Harvard Museum of Natural History.
Chromium is mainly found in natural deposits as ores and other compounds such as chrome ochre ([Cr.sub.2][O.sub.3]),
crocoite (PbCr[O.sub.4]), and ferric chromite (Fe[Cr.sub.2][O.sub.4]).
John Bradshaw, Coast-to-Coast Rare Stones International, Nashua, New Hampshire, USA, for 21 bags containing part-cut crystals of: apatite (Canada and Mexico), cassiterite (Namibia), celestine (Kansas, USA), cerrusite (Namibia),
crocoite (Tasmania, Australia), diaspore (Turkey), oligoclase (Kenya), pollucite (Conneticut, USA), scheelite (Pakistan and Arizona, USA), smithsonite (Namibia), sphalerite (Spain), tourmaline (Maine, USA, and Afghanistan), tugtupite (Greenland), willemite/leucophoenicite (New Jersey, USA) and zincite on calcite (New Jersey); and also for 95 faceted mixed-shape tourmalines, mostly pink, green and blue.
You'll be understanding if, when you obtain a copy of the book, you turn to the Santa Tereza chrysoberyl (page 106: Keith Proctor collection), Morro Velho gold (page 150: Alvaro Lucio collection), Lavra Caba Saco rutile (page 288: Luiz Menezes collection), Brumado dolomite (page 317: Julio Landmann collection), Ouro Preto
crocoite (page 331: Alvaro Lucio collection), Sapo mine fluorapatite (page 347: Jim and Gail Spann collection), Malacacheta autunite (page 357: Luiz Menezes collection), or nearly any one of the stunning specimens of topaz, elbaite, beryl, euclase, etc.
Previous work showed that some bacterial species, including a strain of Pseudomonas chromatophila, can corrode metals present in solid
crocoite, a mineral that artists, including Vincent Van Gogh and Marc Chagall, have used to make yellow or orange paint.
Lead phases detected by X-ray d iffraction include synthetic hydrocerussite ([Pb.sub.3][([CO.sub.3]).sub.2][(OH).sub.2]), synthetic
crocoite ([PbCrO.sub.4]), synthetic phoenicochroite ([Pb.sub.2][CrO.sub.4]O), synthetic anglesite ([PbSO.sub.4]), and possible synthetic plattnerite ([PbO.sub.2]).
To mineral collectors, it is the end-of-the-earth place where the world's finest
crocoite specimens have been found for more than a century, and are still being found, in small, mostly defunct lead mines near the town of Dundas.
The fluorites, pink quartzes, even the delicate greens of some spodumene, the faintly blushing calcites and the rhodochrosites, also sensibly succumb to these exposures, while it is a matter of common annoyance to find that the realgars, cerargyrites, proustites, cuprites,
crocoite, and sulphurs go through changes that slowly alter their substance, texture and appearance.
The black gravel made an interesting yet non-intrusive "matrix" for all sorts of fabulous things, from nuggets of fire opal to elaborate jewelry pieces to wonderful specimens of (for example) green mimetite from the Elura mine,
crocoite from Tasmania, and dozens of species from Broken Hill.
Crocoite, scolecite, mesolite, cerussite--such specimens and other fragile delicacies are highly desired by avid mineral collectors.
At the Main Show, Mike Bergmann (www.mikebergmannminerals.com) was showing off what was left of a group of about 40 elite
crocoite specimens he had recently scored; by Main Show time only eight of them remained unsold.
(www.theadelaidemine.com) showed up at the Main Show with hundreds of first-rate specimens of
crocoite, ranging to large-cabinet size, from a huge pocket (called the Premier Pocket) which was hit in April 2006 in the Adelaide mine, Tasmania.