ADAMITE
Specimen ada-18

Dims: 3.3" x 2.6" x 1.4"(8.4 x 6.6 x 3.6 cm)

Wt: 6.80 oz.(193.0 g)

Mapimi, Durango, Mexico

A splendid cluster of botryoidal Adamite formations adorns this specimen. It has a uniformly pale yellow-green color and the adamantine luster whence it got its name, and is translucent. The orbs that make up the cluster do not exceed 1/2"(1.3 cm) in diameter, and some that are along the edge of the specimen are broken, showing the acicular, radiating habit of the Adamite blades. This botryoidal crust is wedged between a matrix of quartzite and one of limonite. It sparkles quite well.

Dims: 2.7" x 2.0" x 1.7" (6.9 x 5.1 x 4.3 cm)

Wt: 2.51 oz. (71.1 g)

Mapimi, Durango, Mexico

I find the contrast in this specimen most pleasant. Several clusters of green Adamite reside on a rust-red limonite host rock. The Adamite crystals have a pale yellow-green coloration that is greener than most specimens that I have seen from this locality. They do not exceed 0.2" (5 mm) in length and occur in aggregates with curved faces. Their luster is adamantine (of course!) and they are translucent. The limonite base is dull in luster and opaque, and its brown-red coloration is nearly complementary to the yellow-green of the adamite. I find it quite attractive.

Dims: 2.8" x 1.8" x 1.6" (7.1 x 4.6 x 4.1 cm)

Wt: 4.97 oz. (141.2 g)

Mapimi, Durango, Mexico

I like this Adamite specimen especially well because its color ranges from nearly white to yellow-green, and it shows both prismatic and acicular forms of the mineral. The crystals are usually intergrown into crusts and do not exceed 0.3" (8 mm) in length. They have shallow, two-faced domed terminations that are very well-formed and show little damage. Some cross-sections of the crusts, however, show an acicular, radiating tendency at the base of these prismatic crystals. Along with the Adamite, a few white prismatic calcite crystals inhabit one of the crevices in the limonite host rock. As they are at the very opening of the crevice, they are damaged and incomplete. The limonite host has a red-brown color and shows some nearly botryoidal formations that may be left over from a time when the limonite was originally goethite. It is dull, and lends a good contrast to the bright luster and yellow-green color of the Adamite.

Dims: 4.2" x 2.4" x 1.9" (10.7 x 6.1 x 4.8 cm)

Wt: 13.1 oz. (370 g)

Mapimi, Durango, Mexico

The Adamite clusters on this specimen are made up of some rather well-shaped crystals. They occur in the form of long, thin blades with rather complex, shallow wedge-shaped terminations, and show only a very small amount of damage. The blades are very well-formed, however, and reach lengths of nearly 0.5" (1.3 cm). These crystals form 4 separate and distinct clusters that would have almost botryoidal shapes, but they are not "full" enough, and the large crystals form a rather uneven surface. They have a vitreous luster on their prism faces and a dull, waxy luster on their termination faces. They are colorless and transparent near their terminations, but cloud up and become a rusty-red color towards their bases, likely due to included limonite, which makes up the bulk of the base rock on which they rest. Scattered around these large clusters are dozens of tiny Adamite crystals that are crusted over with even more, microscopic Adamites. The limonite host rock has a rather extensive crevice that runs completely through it at one point, which is also lined with more Adamite crystals.

Dims: 2.3" x 1.9" x 1.7" (5.8 x 4.8 x 4.3 cm)

Wt: 3.16 oz. (89.5 g)

Mapimi, Durango, Mexico

The goethite/limonite host rock of this specimen contains a hollow that is partially lined with well-formed, pale yellow Adamite crystals. These crystals occur as orthorombic prisms with diamond-shaped cross-sections that are topped by shallow, two-faced domes. At least one of the crystals is doubly-terminated. There is no visible damage to the crystals, and all of them have a bright, adamantine luster that is accentuated by their clean faces and well-defined edges. They are generally transparent, but most of them show substantial internal fracturing and inclusion that spoils their clarity. There are some, however, that are very clear.

Dims: 3.0" x 1.8" x 1.4" (7.6 x 4.6 x 3.6 cm)

Wt: 5.00 oz. (141.7 g)

Mapimi, Durango, Mexico

A yellow crust made up of sparkling Adamite crystals rests on the iron-based host rock of this specimen. The Adamite crystals that make up the crust do not exceed 0.2" (5 mm) in length and are in excellent condition, showing almost no damage. They have the standard orthorombic bladed crystals with a diamond-shaped cross-section and a shallow wedge-shaped termination. Their luster is bright and nearly adamantine, and all are at least translucent, with some crystals' transparence showing excellent clarity. There are many tiny Adamite crystals scattered around the cluster of larger ones, and more Adamite can be seen in veins in the host rock. The host rock itself is surprisingly heavy, being made mostly out of hematite instead of goethite and limonite. There is much veining in the host rock besides that of the thin lines of Adamite.

Dims: 2.1" x 1.6" x 1.5" (5.3 x 4.1 x 3.8 cm)

Wt: 3.58 oz. (101.6 g)

Mapimi, Durango, Mexico

This specimen contains some of the largest Adamite crystals that I have seen. I count less than 12 crystals on the limonite host rock, and a few of these are broken. However, the largest intact crystal measures 0.4 x 0.3 x 0.3" (1.0 x 0.8 x 0.7 cm) and is in excellent condition, with no damage and smooth, well-defined faces and edges. All of the crystals have the standard orthorombic prismatic form with diamond-shaped cross-sections and shallow, wedge-like terminations, and green-yellow color and adamantine luster. They are nearly transparent, but many internal fractures and inclusions destroy any chance of clarity. The limonite base has some visible layering in it, showing that there is probably still some intact goethite in the host rock. The Adamite crystals on this specimen are quite easy to see.

Dims: 2.8" x 2.5" x 1.4" (7.1 x 6.4 x 3.6 cm)

Wt: 6.02 oz. (170.8 g)

Mapimi, Durango, Mexico

The Adamite crystals of this specimen grow in hollows in the decaying goethite/limonite host rock. They have an orthorombic prismatic form with a diamond-shaped cross-section and are topped by shallow wedge-like terminations. The longest crystals visible do not exceed 0.4" (1.0 cm). One cluster in particular shows their tendency to often radiate outwards from a central point. The crystals have a rich golden color with a tinge of green and an adamantine luster, and are transparent and show considerable clarity. The surfaces of the hollows that house the Adamite crystals are coated with a layer of tiny calcite crystals that are interspersed with a few small Adamites. One crevice extends rather deeply into the host, which may have a small cavern deep inside.

Dims: 1.8 x 1.5 x 1.4" (4.6 x 3.8 x 3.6 cm)

Wt: 1.79 oz. (50.9 g)

Neapami, Durango, Mexico

The bulk of this specimen consists of a nearly complete, rounded cluster of radiating Adamite prisms. There are two smaller clusters that are slightly intergrown with this larger one, but they are both heavily broken and mostly incomplete. The big cluster has dimensions of 1.6 x 1.0 x 0.8" (4.1 x 2.5 x 2.0 cm), and is in moderately good condition- along with the breakage at each end of it, there is an area of light but noticeable crushing damage on its outer surface. The crystals that make up the spray do not exceed 0.8" (2.0 cm) in length, and appear to be very well-formed, though all but their terminations are intergrown. They have a uniform pale green coloration and are translucent to dimly transparent. A small slab of goethite/limonite base rock is stuck to a portion of the spray.

Dims: 3.5 x 2.6 x 1.5" (8.9 x 6.6 x 3.8 cm)

Wt: 6.01 oz. (170.5 g)

Neapami, Durango, Mexico

Several individual Adamite crystals and a few Adamite clusters rest on the gray limestone host rock of this specimen. The crystals do not exceed 0.5" (1.0 cm) and the largest cluster is generally round and has a diameter of 0.8" (2.0 cm)- the other clusters are mostly intergrown with the largest. All the crystals (even those in the clusters) are well-defined and have good orthorhombic prismatic form, with well-defined edges and striated but clean faces that possess the adamantine luster for which they are named. Their color is a pale greenish-yellow, and all are dimly transparent to translucent. When placed under shortwave ultraviolet light, the Adamite produces a moderately bright green glow. Accompanying the Adamite are several broken formations of goethite or limonite. These for

Dims: 2.7 x 1.8 x 1.6" (6.9 x 4.6 x 4.1 cm)

Wt: 5.35 oz. (151.5 g)

Neapami, Durango, Mexico

At least 7 integrown Adamite clusters make up most of this hand specimen. The clusters are all incomplete due to restricted space and their intergrowth with each other, but are in excellent condition, showing almost no fresh damage. They range in diameter from 0.4" (1.0 cm) to 1.1" (2.8 cm), and each is made up of dozens of intergrown Adamite blades. The blades are too intergrown for their form to be effectively studied, but their terminations are well-formed and reflect the standard adamantine luster. All have a rather dirty yellow-green coloration with a hint of brown, and show dim transparence to a shallow depth. A few small calcite crystals accompany the clusters, and only a thin crust of a soft limonite host rock is present.

Dims: 3.8 x 2.8 x 1.9" (9.7 x 7.1 x 4.8 cm)

Wt: 13.8 oz. (391 g)

Neapami, Durango, Mexico

This hand specimen contains some of the largest Adamite clusters that I have seen. All are incomplete, and most are visibly damaged, but the largest of the clusters has a diameter of 1.7" (4.3 cm). Each cluster is made up of scores of intergrown Adamite crystals, many of which are in excellent condition- those clusters that are broken show the radial habit of the crystals. Where intact, these crystals have very good orthorhombic prismatic form, with well-defined edges and clean faces. All have the standard pale yellow-green coloration and adamantine luster of their species, and though some dim transparence is visible on their outer surfaces, the clusters are essentially translucent. They rest on a powery, red-brown goethite/limonite base.

Dims: 2.1 x 1.5 x 1.4" (5.3 x 3.8 x 3.6 cm)

Wt: 2.27 oz. (64.4 g)

Mapimi, Durango, Mexico

A crust made up of scores of small Adamite crystals covers part of the limonite host rock of this large thumbnail specimen. These crystals are quite small and generally do not exceed 0.2" (5 mm) along any axis. They appear to be in generally good condition, however, and possess excellent orthorhombic prismatic form with a diamond-shaped cross-section and flat basal terminations that are truncated by secondary faces. All have the standard pale yellow color with a substantial green tinge and the classic adamantine luster, and are transparent and moderately to very clear. They are accompanied by many slightly larger calcite crystals which rest on top of the Adamite druse, protecting it. Surprisingly few of these calcites are broken, however, and most have excellent trigonal bipyramidal form. They are milky-white in color, have a pearly luster, and are dimly transparent.

Dims: 3.9 x 1.8 x 1.7" (9.9 x 4.6 x 4.3 cm)

Wt: 5.86 oz. (165.9 g)

Mapimi, Durango, Mexico

A crust of crystalline Adamite partly covers the limonite base of this hand specimen. This crust is made up of scores of Adamite crystals that are in good condition and do not exceed 0.1" (3 mm) in any dimension. Their orthorhombic form is is good considering their intergrowth, and all have the pale, dull yellow-green coloration and adamantine luster that are standard for the species.

Dims: 3.0 x 1.9 x 1.5" (7.6 x 4.8 x 3.8 cm)

Wt: 5.69 oz. (161.5 g)

Mapimi, Durango, Mexico

The red-brown limonite base of this piece is partly covered by a cluster of heavily-intergrown Adamite crystals. These crystals are in moderately good condition, showing considerable damage, and do not exceed 0.2" (5 mm) in diameter. All have good orthorhombic prismatic form and the standard pale, dull yellow-green color and adamantine luster of their species.

Dims: 3.3 x 2.2 x 1.0" (8.3 x 5.5 x 2.6 cm)

Wt: 4.27 oz. (121.2 g)

Mapimi, Durango, Mexico

This hand specimen consists of an Adamite crust that likely lined part of a hollow in the limonite host rock. The crust is made up of scores of Adamite crystals that are heavily intergrown and nearly impossible to study as individuals. Their orthorhombic form is difficult to study due to their intergrowth, but appears to be somewhat rounded and warped. All have a pale yellow-green coloration and the standard adamantine luster, and are translucent and cloudy.

Dims: 2.4 x 1.3 x 1.3" (6.0 x 3.3 x 3.2 cm)

Wt: 2.53 oz. (71.7 g)

Mapimi, Durango, Mexico

Two Adamite druses partly cover the limonite base of this hand specimen. Each of these druses is made up of dozens of limonite crystals that do not exceed 0.1" (3 mm) along any axis and are generally in very good condition. Their orthorhombic prismatic form is not very easy to study but appears to be very good. All have the standard yellow-green coloration and adamantine luster and are transparent and dimly to moderately clear, containing internal fractures, cloudy inclusions, or both.

Dims: 3.9 x 3.0 x 1.3" (9.9 x 7.6 x 3.3 cm)

Wt: 8.18 oz. (232.1 g)

Mapimi, Durango, Mexico

This cabinet specimen consists of a goethite/limonite base that is partly covered with scattered Adamite crystals. These crystals do not exceed 0.3" (8 mm) in diameter and are generally in very good condition, as only a few are visibly damaged. Their orthorhombic form is mostly convoluted due to intergrowth, but is still evident and actually good in individual crystals. All have the standard pale, yellow-green coloration and a rather dull, vitreous-to-greasy luster, and are transparent but dimly clear due to inclusions. One face of the limonite base is covered with these crystals, but they are in turn covered with a thin crust of more limonite, hiding their color and luster.

Dims: 4.9 x 3.5 x 3.0" (12.4 x 8.8 x 7.6 cm)

Wt: 1 lb., 5.7 oz. (616 g)

Mina Ojuela, Mapimi, Durango, Mexico

The limonite base of this display piece is partly covered with many rounded, radiating Adamite clusters. Though a few of these are damaged, most are in excellent condition. They contain crystals that reach lengths of 0.4" (1 cm) and have good orthorhombic prismatic form, considering their tight arrangements. All have the common dull yellow-green color and adamantine luster and are translucent. They glow a bright green when placed under shortwave ultraviolet light. A few tiny calcite crystals are also present.

Dims: 2.9 x 2.1 x 1.8" (7.4 x 5.3 x 4.6 cm)

Wt: 5.79 oz. (164 g)

Neapami, Durango, Mexico

This hand specimen consists of a large Adamite botryoidal crystal (with several smaller attached crystals) on a limonite base. All have the standard pale yellow-green coloration and adamantine luster of their species, and though one of the sprays is transparent, the clusters are essentially translucent. Some of the crystals have a partial coating of what appears to be goethite. The green of the adamite and the red of the limonite make for a nice contrast.

Dims: 3.39x1.93x1.50" (8.6x4.9x3.8cm)

Wt: 4.15oz (117.4g)

Mapimi, Durango, Mexico

This is a nice specimen of adamite that shows characteristic pale green crystals against a red limonite backdrop. The crystals are individually diamond shaped (or double diamond) wedges that are often gathered into a rounded dome. The crystals are translucent and have a high luster. The smallest crystals (prismatic with a diamond cross section and variously roof or basal terminations) are transparent. The limonite is unusual, in that it is hard and does not rub off on my fingers. Indeed, there appears to be a druze of crystals along the bottom, possibly calcite, so that there is an area of sparkly red "druzy limonite".

Dims: 1.88x1.36x0.79" (4.78x3.47x2.00cm)

Wt: 0.93oz (26.4g)

Mapimi, Durango, Mexico

A radial growth of light yellow-green adamite crystals is exposed on a limonite matrix. The adamite is transparent and has a vitreous luster, but the appearance is basically translucent due to many internal fractures and crystal boundaries. On one side, a fracture through the crystal reveals the radial growth pattern. Odly enough, there appears to be a shell of some sort surrounding the adamite.