The Demix-Varennes quarry is the type, and only known, locality for varennesite. It is rarely found here, but can be locally “abundant”. However, it is a very brittle mineral, and even when “abundant”, most crystals are broken. This specimen features two or three areas with good, complete, crystals (along with lots of broken ones). There are also very minor amounts of makatite and zakharovite.
In addition, there is a “cute sphalerite” crystal and some unidentified pinkish flakes. The latter might, in fact, be the most interesting thing on the specimen, but the qualitative EDS pattern (“Analysis” tab) doesn’t match any mineral reported from the Saint-Amable sill and the flakes don’t look like any mineral with the Si:Ca ratio (~2:1) implied by the scan. (For example, apophyllite has this ratio, but it doesn’t look like this and it has not been found here.) If you have access to WDS/XRD, this could be a fun thing to play with.
The first pair of photos (FOV 3.5 x 2.5 mm) shows what is probably the best group of varennesite crystals. The one at top right is 1.25 mm wide.
The second pair of photos (FOV 3.6 x 2.6 mm) shows another area with several undamaged, but more inter-grown, varennesite crystals. The one in the center is ca 0.7 mm wide. This photo also shows the pinkish UK.
The third pair of photos (FOV 2.3 x 3.2 mm) shows a crystal (or twin) 1.4 mm wide growing freely on one side. Most of the “zigs-zags” appear to be just how the crystal grew, rather than dings. (The acute angles are sometimes seen in “parquetted” aggregates of varennesite crystals.) The pinkish UK is on the left side of this photo.
The seventh photo (FOV 3.5 x 2.4 mm) shows the small patch of fibrous to bladed pale blue-green makatite. I don’t know what the yellowish flaky/grainy stuff is. Such stuff is often a mixture - not suitable for EDS.
The next photo (FOV 3.5 x 2.4 mm) shows the small, bright yellow, zakharovite aggregates. The central group spans 1.1 mm along the long axis.The pink (mostly broken) crystals are eudialyte.
The next photo (FOV 3. 3 x 2.3 mm) shows a sphalerite crystal (1.3 mm on edge) with numerous re-entrant angles – presumably a twin. It is surrounded by the pinkish UK. Sphalerite itself is fairly common at the Demix-Varennes quarry. The most interesting things about this sample of sphalerite are the association with varennesite and the peculiar twinning.
This is a rather large, and somewhat heavy, “micro”. Unfortunately, the matrix is very tough, and does not split predictably. Unless your splitter is a lot better than mine – and you have a lot of experience with it – I would advise leaving it as is. (The brittleness of the varennesite should be kept in mind.)
Single item shipping weight (no case) is 6.3 oz (179 g). For shipments outside the USA, up to a total weight < 8 oz (225g), this can be combined with a small item or two from this or other auctions for the same postage.
Within the USA, postage for total weights up to 13 oz, ranges from $4.50 to $6.50 (including packing etc) regardless of destination. Above 13 oz, I will use Priority Mail ($7.25 - $9.20 including packing – varies by destination).
