Coulda, shoulda, woulda. MSH “shoulda” been the TL for ferroceladonite. But it isn’t. Nonetheless, MSH is probably the best place in the world for finding this rare mineral. It is fairly rare here, not found very often. However, when found, it tends to cover everything in sight! This occurrence is rather different. Instead of occurring as a thin coating or as a powdery cavity filling, the ferroceladonite occurs as distinct “spurs” in a crust ca 0.2 mm thick in cavities in hisingerite. Both species were identified at the ROM via EDS. (Hisingerite has a very poor to non-existent PXRD pattern.)  A very unusual find – perhaps unique. I have only two of these, and I have not seen any others.

FOV is 3.65 x 2.45 mm in the first photo, 6.6 x 4.7 in the second. The second (larger) cavity is also visible in the full-view photo. The resinous brown stuff is the hisingerite. It looks like dark brown sphalerite, except that the latter has very good cleavages, whereas hisingerite has a conchoidal fracture.

Single item shipping weight is 2.9 oz (82 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).