Dims: 4.6 x 0.2 x 0.2" (11.7 x 0.5 x 0.5 cm)
Wt: 14.0 g w/ base
Cave-In-Rock, Illinois, U.S.A.
Easily the most unusual Marcasite specimen that I have seen from this locality, this specimen consists of a long, thin stalactitic formation that is exceptionally straight for most of its length. I would guess that calcite might make up or have made up the core of this formation, and the Marcasite subsequently coated it. The Marcasite is crystalline, though the crystals do not exceed 3 mm in any dimension. However, they are in excellent condition, as they appear to be undamaged. The visible crystals have an octahedral form, a deep golden color, and a metallic luster. Two other such stalactites intersected with this one, but they are broken, and only small sections remain. The tip of the stalactite is quite unusual, as it curves rapidly just before it terminates; it almost has the shape of the bill of a flamingo (see the close-up image)! There is no host rock present, and the stalactite is attached to a square acrylic base with a hot glue.