WITHERITE
Specimen wit-1

Dims: 1-3/4" x 1-1/2" x 1-1/8"

Wt: 2.12 oz

Cave-In-Rock, Illinois, U.S.A.

This off-white pair of intergrown hexagonal columnar crystals is one of the neater specimens that I have seen come from the Cave-In-Rock locality of Illinois. The crystals seem to be made up of stacked platelets of the mineral, so the prism faces are heavily ridged. They have a dull luster and a rounded, indefinite terminations. A substantial portion of one of the crystals is missing, but seems to have undergone some healing, possibly with calcite or aragonite. As shown in the close-up frame, it is quite fluorescent, giving off a bright blue glow. There is a bit of the calcite/aragonite as a matrix.

Dims: 1.8 x 1.5 x 1.1" (4.6 x 3.8 x 2.8 cm)

Wt: 1.17 oz. (33.3 g)

Alma Mine, Hardin County, Illinois, U.S.A.

This small thumbnail specimen contains the finest Witherite crystal that I have seen in my travels. This crystal measures 1.0" (2.5 cm) long and 0.6" (1.5 cm) in diameter and shows no damage that I can see. It has the best hexagonal prismatic form that I have seen in Witherite, and is topped with a steep hexagonal pyramidal termination that is almost perfectly symmetrical. It has a milky-white coloration and a dull pearly-to-vitreous luster, and is very dimly transparent. There is a much smaller crystal laying about 4 mm from the larger one. It is the same in all respects except for its form, which is basically that of a hexagonal bipyramid. The host rock is amorphous and contains shards of a few small, violet fluorite cubes.

Dims: 2.6 x 2.4 x 1.3" (6.6 x 6.1 x 3.3 cm)

Wt: 6.64 oz. (188.2 g)

Minerva Mine, Hardin County, Illinois, U.S.A.

A thick crust of crystalline Witherite rests on the carbonate-bearing host rock of this specimen. The crust is made up of scores of intergrown pseudohexagonal prismatic Witherite crystals that are generally in good condition and do not exceed 0.6" (1.5 cm) in length. Their form is good considering their intergrowth, with well-defined edges and heavily striated faces that are dull and waxy in luster. All have a color that ranges from a dull cream to gray, and all are translucent and cloudy. A small vein of more massive material extends into one area on the host rock, which looks like a pale brown limestone. A few tiny bits of violet and colorless fluorite rest on the crust, too.

Dims: 0.7 x 0.6 x 0.6" (1.8 x 1.5 x 1.5 cm)

Wt: 19.7 g w/ specimen box

Hardin County, Illinois, U.S.A.

This thumbnail specimen consists of a single, moderately warped Witherite crystal that may have started out as two crystals which grew together. This crystal is apparently in excellent condition, as no fresh breakage is visible. Its hexagonal prismatic form is still quite discernable, though some edges are faint and some faces are quite uneven. It has the classic milky-white color and dull waxy-to-matte luster of its species. There is no host rock present. The accompanying documentation did not say so, but I believe that this piece came from the Minerva Mine, the best-known producer of Witherite in the U.S. state of Illinois.

Dims: 1.7 x 1.7 x 1.4" (4.3 x 4.3 x 3.6 cm)

Wt: 4.0 oz. (113.6 g)

Minerva Mine, Hardin County, Illinois, U.S.A.

At least 2 rounded, intergrown clusters of Witherite crystals rest on the white base rock of this specimen. These clusters are very warped and intergrown, so it is difficult to assess their actual dimensions. Each is made up of dozens of small hexagonal prismatic crystals that are generally in very good condition, as only a few are damaged or broken. These crystals are heavily intergrown also, so that one cannot accurately determine their size, but they all have excellent hexagonal prismatic form with well-defined edges, clean faces, and basal terminations. All have a dull cream color and a waxy luster, and are dimly transparent. They glow a dim blue under shortwave ultraviolet light. The clusters actually form a druse that is about 0.4" (1.0 cm) thick which partly covers what appears to be a massive calcite base.

Dims: 0.9 x 0.8 x 0.7" (2.3 x 2.0 x 1.8 cm)

Wt: 18.0 g w/ specimen box

Cave-In-Rock, Hardin County, Illinois, U.S.A.

This thumbnail specimen consists of a single Witherite crystal that is heavily intergrown with a broken Witherite base. The crystal has dimensions of 0.6 x 0.6 x 0.6" (1.6 x 1.6 x 1.5 cm), and it is in very good condition- its lack of completeness is not due to damage. Its hexagonal form is excellent, and it takes on the shape of 2 hexagonal pyramidal terminations that have been stuck base-to-base. Its color is a dull, creamy white, and its luster is dull and waxy. The piece is hot-glued into a plastic specimen box.

Dims: 2.9 x 2.0 x 1.3" (7.3 x 5.0 x 3.3 cm)

Wt: 5.7 oz. (160 g)

Cave-In-Rock, Hardin County, Illinois, U.S.A.

This small cabinet piece consists of a cluster of rounded Witherite prisms that extend from a dull brown base rock. These crystals are generally in good condition, though a few are obviously damaged, and reach dimensions of 0.9 x 0.6 x 0.3" (2.3 x 1.5 x 0.8 cm). Their hexagonal prism is quite good, though all surfaces are heavily patterned, and both surfaces and edges are somewhat curved. They have the classic dull, creamy white color and waxy to pearly luster, and are translucent to dimly transparent. The base is likely made up of limestone, and a few small hollows contain countless tiny dogtooth calcites.