This specimen features two minerals that are very rare at MSH (and not exactly common world-wide): makatite and tuperssuatsiaite. There is not that much of the tuperssuatsiaite, but perhaps 80% or more of the specimen is makatite. Quite remarkable for MSH. The makatite & tuperssuatsiaite (partly intergrown) envelop pale greenish crystals of (blah) pectolite and small, but well-formed, crystals of a dark amphibole, probably Arfvedsonite (not analyzed).
This is the only specimen of makatite from MSH that I have (or have ever seen).
The first two pairs of photos (FOV 4.55 x 6.1 mm and 6.6 x 4.35 mm resp.) are close-ups of some of the makatite showing the typical fibrous to bladed appearance, highlighted against two of the better amphibole crystals. The brownish fibers in both pairs of photos are tuperssuatsiaite. In the first of these pairs of photos, the amphibole is 2.1 mm tall.
The next pair of photos shows one side of the entire specimen. It’s rather “lumpy” and not terribly attractive, but, as you can see, there is a great deal of makatite – all the white areas.
You may notice that the makatite looks very similar to the pectolite that is sometimes found in the igneous breccia at MSH. But this is makatite, not pectolite. For one thing, there are also pectolite crystals, some euhedral, embedded in the makatite. More importantly, as shown in the next pair of photos, pectolite has a violet-pink LW UV response, whereas makatite has a weak yellow white response (stronger pale green in SW). (Incidentally, these photos show another side of the specimen.)
Note that my UV photo is just a very rough approximation. These two minerals are not always fluorescent, and in this case the response was rather feeble. My camera sensor didn’t really handle things too well. However, my point is this: You would never mistake the UV response of pectolite for that of makatite.
The last pair of photos are views of other sides of the specimen. The yellowish areas are the tuperssuatsiaite.
Single item shipping weight (with TN case) is 3.2 oz (91 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 for total weights up to 13 oz ranges from $4.25 to $6.50 (including packing etc) regardless of destination. Above 13 oz, I will use “own box” Priority Mail. The rate, including packing, varies by destination from $7.25 to $9.50.
