What’s special about this specimen? It’s the numerous crystals of ancylite-(Ce) of the very rare pseudo-hexagonal bi-pyramidal habit illustrated in the Min Rec special issue on MSH (1990, p. 295). The crystals are very small, but the habit is very rare.
As a bonus, the ancylite sits on attractive sprays of “astrophyllite” and peculiar “crystals” of calcite (possibly pseudomorphs). According to EDS, the “astrophyllite” is about half-way between astrophyllite and kupletskite. (See the “Analysis” tab). Additional minerals include orange “eudialyte” (probably kentbrooksite), “arfvedsonite” (not analyzed), and a dark mica (probably annite).
The first pair of photos (FOV 1.0 x 0.75 mm) shows a few isolated, hexagonal, crystals of ancylite-(Ce). They are only 0.2 mm in diameter.
The next photo (FOV 1.9 x 1.1 mm) shows several, even smaller (ca 1/8 mm) ancylite crystals, some impaled on a thin blade of “astrophyllite”. You will need 50-60X (and the patience to fiddle with lighting) to see these crystals clearly.
The next pair of photos (FOV 3.4 x 2.45) shows slightly larger (0.25 mm) crystals of ancylite on calcite “crystals” (to 2.6 mm).
The next photo (FOV 1.9 x 1.4 mm) is a close-up of one of the largest calcite “crystals”. The morphology isn’t impossible for calcite, but is so suggestive of nenadkevichite, that a sample was analyzed. The result was “calcite”. In retrospect, the “crystals” were found to dissolve quickly and completely in HCl with the usual “fizz”. Calcite after nenadkevichite would be strange indeed, but several others were fooled by these things – no one suggested calcite!
The next pair of photos (FOV 4.7 x 7.0 mm) shows some of the “astrophyllite” along with many more of the “calcite” crystals.
The next photo shows most of the “astrophyllite” on the specimen. The FOV is 3.2 cm wide.
The next to last photo shows the only relict euhedral portion of the “kentbrooksite”. It appears to be only a cust on whatever has replaced most of the crystal. (No attempt was made to identify the replacement. The results are often inconclusive – and it gets expensive trying to analyze everything on a specimen.)
The last photo is obviously a full view.
This is a fairly heavy item. Single item shipping weight (no case) is 6.4 oz (210 g). For shipments outside the USA, up to a total weight < 8 oz (225 g), this can be combined with small items from this or other auctions for the same postage. Above a total weight of 225 g (up to 450 g), postage increases by $6-9, depending on destination.
Within the USA, postage increases by about $0.20 per ounce. Above 13 oz, I will use Priority Mail ($9.25 including packing).
