Columbite-(Fe) is a very rare mineral at MSH. When found, the crystals are often embedded in matrix and broken. The crystals on this specimen grow freely in small cavities. They are small, but good, examples for the locality – at least in my experience. The columbite was confirmed via EDS on two other specimesn (see the “Analysis” tab). The columbite is associated with gmelinite-Na and complex crystals of siderite, some of it in odd “layer-cakes” with muscovite  (both also confirmed via EDS). In addition, there are a few small unidentified “beehive” shaped masses. Probably these are “donnayite group” or parisite-(Ce), but they were not analyzed.

The first pair of photo (FOV 1.1 x 1.3 mm) is a close-up of the most interesting columbite crystal (or twin). It spans 0.4 mm. You can see it clearly with 15X, but these photos were taken at the equivalent of about 60X.

The second pair of photos (FOV 1.15 x 1.4 mm) shows the other well-formed crystal on the specimen. It is only about 0.3 mm in diameter. There are also two other, small, embedded and damaged, columbite crystals (not shown).

The next pair of photos (FOV 2.6 x 2.1 mm) shows the pale tan rosette of gmelinite- Na. It spans ca 2.0 mm.

The last pair of close-up photos (FOV 6.2 mm x 3.9 mm) shows the largest and best siderite-muscovite “layer-cake”. The muscovite may be replacing something. On other specimens, it forms octahedral aggregates, hollow on the inside.

Single item shipping weight 3.5 oz (100 g). Outside the USA, the stated postage and packing rate applies up to a total weight of 8 oz (225 g).

Within the USA, there is a nominal increase of $0.20 for each additional ounce. Above 13 oz, I will use Priority Mail. Up to 16 oz, the “own box” Priority rate is $9.25 (including packing).