“FOV ~ 6+ cm high. Via John Cianciulli and KH. MOB coll. MSH is famous (notorious?) for many unusual pseudomorphs. This one seems unique in my experience. It consists mostly of yellow calcite and unid vermiform gray stuff replacing fairly large, well formed xls of distinctive shape. But despite that I am unable to figure out what the precursor was. Jan 2014: Siderite from Panasqueira appears to have a habit similar to the precursor. See Min Rec V45 #1 p. 46 fig 92 & 93. But I have not seen this habit for siderite at MSH - which doesn't mean all that much. The olive/brown siderite is just an accessory on this side of the specimen. But it too forms a pseudomorph of a large prismatic xl on the back (see child photo). The gray stuff looks like some fluorite "mud" - replacing yet something else. In addition, there are small natrolite/gonnardite prisms sprinkled about. Update April 2012: I have now found a specimen of calcite from MSH where the xls look much like the "xls" in this photo. So perhaps it is a PS of calcite after calcite! I may try to add a photo of these calcite xls at some point. ”

“FOV ~ 6+ cm high. This is a stereo child photo. ”

“FOV ~ 6+ cm high. MOB coll. This is a child photo. This side shows the (partial) PS of siderite after a large prismatic xl. It slso shows more of the "faces" of the calcite(+?) pseudomorphs. ”