. Bulletin of the British Museum (Natural History), Mineralogy. CHROMATES OF LEAD C 399. Fig. 7. Hemihedrite, Arizona ; after Williams and Anthony, 1970. assigned, but the oxygen was determined by difference with a probable error of ± 2%, so that the composition could lie anywhere in the range Pb^iCrOigto PbiiCrOig. SOME DOUBTFUL SPECIES Jossaite. Breithaupt (1858) described another species from Berezov. No chemical analysis was given but chemical tests by Plattner, cited in his paper, indicated that it was a chromate of lead and zinc and, possibly, cadmium. The specific gravity was 5*2 but Br
. Bulletin of the British Museum (Natural History), Mineralogy. CHROMATES OF LEAD C 399. Fig. 7. Hemihedrite, Arizona ; after Williams and Anthony, 1970. assigned, but the oxygen was determined by difference with a probable error of ± 2%, so that the composition could lie anywhere in the range Pb^iCrOigto PbiiCrOig. SOME DOUBTFUL SPECIES Jossaite. Breithaupt (1858) described another species from Berezov. No chemical analysis was given but chemical tests by Plattner, cited in his paper, indicated that it was a chromate of lead and zinc and, possibly, cadmium. The specific gravity was 5*2 but Breithaupt was clearly not confident of this value. A prism angle of 110° to 118° was also given. The colour was orange. Breithaupt had kept the material for six years hoping to get more for a complete description and then, giving up, published this short note. Jossaite has never had much success as a mineral. Only B. Silliman, Jr (1881) has reported it from elsewhere, namely on a suite of specimens sent to him from a locality 20 miles north-east of Vulture in Arizona. A number of collectors, notably the late Ed McDole (deceased, 1970), have searched for this locality in vain. Recently I found a fine suite of chromates the same distance from Vulture but in exactly the opposite direction. Among these was a chromate of lead and zinc, but it does not fit Breithaupt's scanty descrip- tion. Furthermore, I have examined a specimen of 'jossaite' from the National Museum (R 6032) and shown it to be crocoite ; it fitted Breithaupt's description rather well.^ Jossaite remains a mystery and is probably a myth. A. Arzruni (1885), in an important contribution to the geology of the Berezov area, lists the minerals found in the district :^ anglesite, azurite, beudantite, bind- heimite, bismutite, bismuth ochre, calcite, caledonite, cerussite, chalcedony, chalco- pyrite, chlorite, chromite, chrome ochre, chrysocolla, covelline, crocoite, dolomite, fuchsite, galena, garnet, goet
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