This is a somewhat unusual specimen of nenadkevichite with gaidonnayite (TL) from the famous Poudrette pegmatite. The unusual part is the color – most of the nenadkevichite crystals are more or less dark gray. EDS (see the “Analysis” tab) shows a rather high Ti peak, i.e. composition in the nenadkevichite-korobitsynite series, but still closer to nenadkevichite than to korobitsynite. PXRD confirms “nenadkevichite” (i.e. nenadkevichite group).

The first pair of photos (FOV 3.75 x 2.5 mm) shows several aggregates of nenadkevichite laths. The largest (top) spans 1.75 mm. The small, clear/white (zoned), crystals are gaidonnayite.

The second pair of photos (FOV 2.0 x 2.5 mm) shows a smaller, lighter colored, aggregate with laths to ca 1.0 mm.

The third pair of photos (FOV 4.4 x 6.8 mm) is a broader view showing both the dark gray (1.75 mm) aggregate from the first pair of photos and a much lighter 1.5 mm aggregate (top). The glassy gaidonnayite crystals are <= 0.5 mm.

Single item shipping weight (no case) is 3.7 oz (105 g). For shipments outside the USA, up to a total weight < 8 oz (225g), this can be combined with items from this or other auctions for the same postage.

Within the USA, postage increases by about $0.20 per ounce. Above 13 oz, I will use Priority Mail ($9.25 including packing).