GYPSUM
Specimen gyp-37
$ 300.00Dims: 21.4 x 1.4 x 1.4" (54.4 x 3.6 x 3.6 cm)
Wt: 3 lbs., 0.9 oz. (1.4 kg)
Chihuahua, Mexico
A single, long Selenite crystal makes up this large cabinet specimen. It is in good condition, showing damage only where other, partly intersecting crystals were separated from it. These damage areas generally take the form of shallow geometric depressions that do not extend more than 0.3" beneath the outer surface of the crystal, and expose flat, clean surfaces that are evidence of the layering effect of its growth. Its monoclinic prismatic form is excellent, as all edges are well-defined and the faces are mostly clean and possess a bright pearly luster. Portions of each face are covered, however, by a dull white crust- this crust is made up of small, tight sprays of tiny Gypsum crystals that are heavily intergrown. There are also a few small but visible Gypsum crystals on the crusts, but these do not exceed 0.2" (5 mm) along any of their axes. The Selenite is colorless, transparent, and moderately clear, as it contains many internal fractures and inclusions. The most noticeable inclusions are thousands of tiny formations of brown hematite or limonite that likely have a dendritic habit. They are aligned in planes beneath the surface of the crystal and collectively form a large phantom that runs along 3/4 its length. Close examination at the termination of the phantom will reveal that there are actually 2 of them, at least one of which is accompanied by another layer of intergrown, tiny Gypsum clusters that were enveloped during growth. There is no host rock, of course.