MSH is the TL for gaidonnayite and most (but not all) of the best specimens come from here. At MSH, gaidonnayite is often heavily twinned. This example from the Poudrette pegmatite features a pair of crystals with exceptionally simple morphology. The specimen is unusual in that the gaidonnayite is associated not only with small yellow-purple cubes of fluorite but also with a “carpet” of tiny pink crystals of fluorapatite. Fluoraptite is moderately common in many environments at MSH, but pink is a very unusual color. These crystals are very small, and not easily recognized as “apatite”. Because of their very unusual pink color, they were analyzed in the hopes of finding britholite, but no such luck. (See the “Analysis” tab. EDS can not distinguish fluorapatite from hydroxylapatite, but almost all “apatite” at MSH has been found to be fluorapatite.)

The gaidonnayite, fluorite, and a bit of the apatite are shown in the first two pairs of photos (FOV 3.4 x 2.4 mm and 2.35 x 3.55 mm). The top face of the gaidonnayite spans 0.95 mm. Altogether, the gaidonnayite crystal is ca  1.7 mm – a good size for the species. Note that the crystal is translucent and slightly iridescent - as was typical in this occurence from the Poudrette pegmatite. The fluorite cubes are <= 0.55 mm on edge.

The third pair of photos (FOV 4.5 x 5.4 mm) is a broader view showing more of the apatite.

Single item shipping weight is 3.1 oz (88 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).