ARAGONITE
Specimen ara-13
$ 20.00Dims: 1.1" x 0.9" x 0.7"(2.8 x 2.3 x 1.8 cm)
Wt: 1.19 oz.(33.6 g) w/ box
Tuscany, Italy
These two small geode halves are lined with needle-like Aragonite crystals. The crystals have a pearly-to-dull luster and are colored by rust that may have leached from the other mineral in the geode as it decayed. This other mineral, called kutnahorite, is present in the form of rusty-brown botryoidal formations that rest among the Aragonite needles. They are opaque and have a generally dull luster, but there are a few formations with more of a silky luster. The skin of the geode is made of a shale or a mudstone, and its cross-section makes me think that maybe it formed as the septarian nodules from Utah, U.S.A. did, where the skin started out as small mudballs that dried and cracked, and then were compressed into stone, and subsequently filled with carbonate "goodies".