This lot consists of two specimens of nenadkevichite with very different habits. Nenadkevichite is uncommon at MSH, but very rare world-wide.

The first specimen (1.6 x 2.3 x 3.4 cm) features unusual colorless, water-clear, laths of nenadkevichite with small “puff-balls” of franconite. The nenadkevichite crystals have “chisel” terminations and are <= 0.95 mm long. They were verified via PXRD. The first three photos are for this specimen. FOV in the close-up photos is 2.3 x 3.3 mm. You will need 30X to view the crystals.

Note: On larger specimens, franconite can usually be distinguished from hochelagaite by its yellow SW UV response. Even though there are some other franconite balls on the specimen, the aggregates are too small to see a clear UV response. But similar specimens from this area (either the “top” of the Poudrette pegmatite or a neighboring pegmatite) appear to be all franconite. (Some have been analyzed.)

The dark background in these photos is very dark brown siderite. The blocky whitish crystals (partly coated by “cavity scum”) are microcline. There are also some tiny natrolite prisms with glassy cores and white exteriors (possibly gonnardite). Just for information, there may also be one very tiny crystal of thomasclarkite-(Y), but it is so small I can’t be sure. (The arrow points to it.)

The last four photos are for the second nenadkevichite specimen (1.1 x 1.5 x 1.3 cm)

As shown in the first of these photos (FOV 2.0 x 2.8 mm), the nenadkevichite crystals on this specimen are pinkish and translucent. They are sharply formed and very lustrous - but they are oddly grooved. The longer crystal on the right (2.1 mm) has a grove or indentation running the almost the whole length of the crystal. This groove is somewhat encrusted, so it does not appear as lustrous as the rest of the crystal.

The next pair of photos (FOV also 2.0 x 2.8 mm) is a slightly different view which highlights the lustrous parts of the crystals on the left. In these photos, the crystal on the right appears to be rather dull, but the pinkish color is more in evidence.

The nenadkevichite crystals can also be seen at top center in the “full-view” photo.

The nenadkevichite is associated with small rhodochrosite rhombs and tiny, stubby, white natrolite prisms.

Combine shipping weight 3.6 oz (100 g). For shipments outside the USA, up to a total weight of 8 oz (225 g), this could be combined with other items from this or future auctions for the same postage. If you wish to keep an “open box”, you must let me know.

For shipments within the USA, there is a nominal increase of about $0.20 for each additional ounce. Above 13 oz I will use “own box” Priority Mail ($9.25).