THE MINERAL SPHALERITE
- Chemistry: (Zn, Fe)S, Zinc Iron Sulfide
- Class: Sulfides
- Group: Sphalerite Group
- Uses: major ore of zinc, rarely cut into gemstones, mineral specimen
Specimens
Sphalerite is one of the very few minerals that has a total of six directions of cleavage. If all of them were to be perfectly cleaved on a single crystal it would form a rhombic dodecahedron. Identifying all six directions in a single cleaved crystal is quite difficult due to the multiple twinning and the many directions. Only the fact that there is abundant cleavage at different directions can easily be seen in most cleaved specimens.
Sphalerite can be difficult to identify because of its variable luster, color, abundant but obscured cleavage and crystal habits. So difficult was sphalerite for miners to distinguish from more valuable minerals such as galena, acanthite and tetrahedrite, that they named it sphalerite which is Greek for treacherous rock and blende is German for blind or deceiving.
The
The twinning of sphalerite is also special. It can form a spinel twin which is a specialty of the mineral spinel. The spinel twin is where a tetrahedral crystal is twisted in the middle so that three points of the tetrahedron are in alignment with the other three points. These crystals are not usually completely developed in sphalerite but the indentations that the twinning causes are usually seen on some crystals in almost every specimen. A twin type for some reason called a "chicken twin" or "hen" forms a sort-of football shaped twin.
Sphalerite is a polymorph with two minerals, wurtzite and
Sphalerite's structure is analogous to the diamond structure. If every other carbon in the diamond structure is replaced by a sulfur atom and the remaining carbons are replaced with either a zinc or an iron atom then basically the mineral is sphalerite.
Sphalerite is by no doubt the most important ore of zinc, an industrially and at times strategically important metal. Other zinc ores include hemimorphite, smithsonite, willemite, franklinite and zincite. Although its importance as an ore of zinc is undisputed, it is a very attractive and a very interesting mineral for collectors as well.
PHYSICAL CHARACTERISTICS:
- Color is typically black but can be brown, yellow, reddish, green, and less commonly white or colorless.
- Luster is adamantine or resinous or submetallic to earthy in massive forms.
- Transparency crystals are transparent to translucent.
- Crystal System is isometric; bar 4 3m
- Crystal Habits can be complicated with the rhombic dodecahedron, tetrahedron and combinations of these having cubic and tristetrahedron faces giving the crystals multiple faces of often indistinct forms. To add more confusion to the indistinct crystals, twinning is common and sometimes pervasive. Massive forms are common and can be granular, earthy, botryoidal, concretionary and fibrous. An aggregate of botryoidal crusts with layers of wurtzite and galena is called "Schalenblende" is sometimes cut and polished as an ornamental stone.
- Cleavage is perfect in six directions forming dodecahedrons.
- Fracture is conchoidal, but rarely seen because of frequent cleavage.
- Hardness is 3.5-4
- Specific Gravity is approximately 4.0 (heavier than average, but light when compared to most metallic minerals)
- Streak is yellow to light brown (unusually light colored for a normally dark mineral).
- Other Characteristics: Striations on tetrahedral faces,
triboluminescent (meaning it may glow if crushed), an index of refraction of 2.37 - 2.42, a dispersion (fire) of 0.156 and finally sphalerite is pyroelectric (meaning that it forms a slight electrical charge when heated or cooled). - Associated Minerals almost always include galena, pyrite, fluorite, chalcopyrite, quartz, calcite, magnetite, pyrrhotite and many others.
- Notable Occurrences include Tri state area near Joplin, Missouri; Rosiclare, Illinois; Elmwood, Tennessee, USA; Broken Hill, Australia; Italy; Spain; Burma; Peru; Morocco; Germany and England.
- Best Field Indicators are crystal habits, streak, cleavage, high luster, softness and twinning.
 Amethyst Galleries' Mineral Gallery MINERALS |
SPHALERITE specimen sph-1
$ 55.00
$ 55.00
Dims: 5-1/2" x 4-1/2" x 1-1/2"
Wt: 1lb., 4 oz
Elmwood Mine, Tennessee, U.S.A.
One of our selection of Elmwood Mine Fluorites, this specimen features a cluster about 1-1/2 inches by 3-1/2 inches by 2-1/4 inches, resting on a base of Dolomitic limestone. Its crystals are dark, clean, and clear, as with most Elmwood pieces, and individual crystals reach up to 1/2 inch high and 1/2 inch long. There is a small amount of damage to a few of the terminations. A partial Fluorite cube hides in the shelter of the large cluster.
sph-1 ($ 55.00)
Elmwood Mine, Tennessee, U.S.A.
SPHALERITE specimen sph-5
$ 39.00
$ 39.00
Dims: 4" x 2-1/8" x 1-7/8"
Wt: 8.8oz
Hardin County, Illinois, U.S.A.
These exceptional-quality Sphalerite crystals are very cleanly-faced, clear, and attain up to a 1/2-inch diameter. They are consistent in shape, each with a dodecahedral formation that is unusual for Sphalerite. Joining in the fun are some rather rounded but still distinctly crystalline Calcites and two small clusters of heavily-cleaved Fluorite crystal segments. This is a favorite specimen of mine- the Sphalerites are some of the best I've seen from this locality.
sph-5 ($ 39.00)
Hardin County, Illinois, U.S.A.
SPHALERITE specimen sph-6
$ 72.00
$ 72.00
Dims: 4-1/2" x 2-1/2" x 2"
Wt: 1 lb., 7.2 oz
Ancash, Peru
These crystals of Sphalerite, with a comparatively dull luster and black color due to a high iron content, do not exceed 1/4 inch in diameter. They are, however, very well-formed, coating a matrix of of massive (it's large, too!) Pyrite that itself exhibits a small amount of crystallization on some of its surfaces. This is a somewhat unusual piece due to its high iron content, and even fooled Steve for a little while, as he was used to seeing the lighter-colored and more lustrous Elmwood Sphalerite.
sph-6 ($ 72.00)
Ancash, Peru
SPHALERITE specimen sph-10
$ 90.00
$ 90.00
Dims: 4.0" x 3.1" x 3.0"(10.2 x 7.9 x 7.6 cm)
Wt: 1 lb., 9.4 oz.(719 g)
Huaron Mine, Ancash, Peru
This particular specimen is composed of over 90% Sphalerite by weight. The crystals are large(almost 1" or 2.5 cm along an edge) and very well-formed, with a small amount of damage. They have an adamantine luster and a dark brown color that is only evident through damage; the crystals are barely translucent, even under a halogen light. The crystals have a tetrahedral form with corners that are truncated by triangular faces. Among the profusion of Sphalerites are the occasional pyrite cube and transparent quartz crystal. These are some of the largest, nicest Sphalerite crystals that I have seen from this locality.
sph-10 ($ 90.00)
Huaron Mine, Ancash, Peru
SPHALERITE specimen sph-12
$ 80.00
$ 80.00
Dims: 3.7" x 3.0" x 2.5" (9.4 x 7.6 x 6.4 cm)
Wt: 15.1 oz. (429 g)
Hardin County, Illinois, U.S.A.
This specimen from the mid-U.S. state of Illinois is made up mostly of Sphalerite by weight. The Sphalerite occurs as heavily striated tetrahedral crystals that range in size from a few millimeters to about 0.7" (1.8 cm) along an edge. The striations denote "steps" that truncate the faces and edges of each crystal, creating what could be called a hopper effect. Most of the larger crystals show some form of damage, and a few are heavily cleaved and incomplete. All of them have a nearly black coloration and an adamantine luster that is interrupted by the striations. Some of the small crystals are translucent, showing a brown coloration, but most are opaque. There is a thin crust of dolomite visible between the Sphalerites, and a few crystals are present. It is a lovely specimen tSPH-12
sph-12 ($ 80.00)
Hardin County, Illinois, U.S.A.
SPHALERITE specimen sph-13
$ 75.00
$ 75.00
Dims: 3.8" x 2.5" x 1.5"(9.7 x 6.4 x 3.8 cm)
Wt: 10.58 oz. (300.0 g)
Huaron Mine, Ancash, Peru
Composed of over 70% Sphalerite by weight, this specimen consists of several intergrown partial octhaedral crystals with a few quartz and intergrown pyrite crystals. The largest of the Sphalerites measure over 1.0" (2.5 cm) along an edge- they are some of the largest in our selection! They appear black in coloration, but have dark brown highlights on the few spots of visible damage, and have a submetallic luster. Some areas at the very edge of the specimen are translucent, showing a brown coloration, but the specimen is mostly opaque. The quartz crystals that are scattered in clusters on the specimen are transparent and clear, and do not exceed 0.3" (8 mm) in length. They are accompanied by many intergrown pyrite cubes that have good form, the standard pale gold color and metallic luster, and don't exceed 0.4" (1.0 cm) alonSPH-13
sph-13 ($ 75.00)
Huaron Mine, Ancash, Peru
SPHALERITE specimen sph-14
$ 115.00
$ 115.00
Dims: 7.6" x 5.2" x 3.3"(19.3 x 13.2 x 8.4 cm)
Wt: 8.3 lbs. (3.8 kg)
Huaron Mine, Ancash, Peru
Though this specimen contains many impressive pyrite crystals, its mass is made up mostly of Sphalerite, in both crystalline and massive forms. The specimen is likely a section of a crust of Sphalerite on which grew pyrite and quartz crystals. There are only a few visible Sphalerites that exceed 0.2" (5 mm) in diameter; most are very small and heavily intergrown, so that only one complete face of each is visible. The larger crystals are more exposed, though still incomplete, and have octahedral tendencies. Like all of the Sphalerite material that is visible, they have a bright, subadamantine luster on their broken faces, and a duller, almost waxy luster on their intact faces. Their color is black with brown highlights, and they are all opaque. The pyrites are in very good condition, with only a small amount of damage on one side, and have rounded cubic fSPH-14
sph-14 ($115.00)
Huaron Mine, Ancash, Peru
SPHALERITE specimen sph-15
$ 30.00
$ 30.00
Dims: 1.6" x 1.3" x 0.9" (4.1 x 3.3 x 2.3 cm)
Wt: 1.40 oz. (39.8 g)
Naica, Chihuahua, Mexico
Though this specimen is not much larger than thumbnail size, the excellence of form in the crystals that make it up are delightful. The base of the piece makes up most of its mass, and is made of intergrown crystals Sphalerite. Though they are mostly covered by other materials, some of the crystals are visible and have the standard complex cubic-based form, adamantine-to-submetallic luster, near-opacity, and brown color. They seem to average approximately 0.3" (8 mm) in diameter. On top of this base lays a cluster of tiny, trigonal "dogtooth" calcite crystals that do not exceed 2 mm in length. They are colorless, transparent and somewhat clear, and have a pearly luster and almost no visible damage. Nearby on the Sphalerite base rest at least 3 separate clusters of small, intergrown fluorite crystals. They have a cubic form and grow so as to be all aligned in their clusters, appearing aSPH-15
sph-15 ($ 30.00)
Naica, Chihuahua, Mexico
SPHALERITE specimen sph-16
$ 32.00
$ 32.00
Dims: 3.9" x 2.4" x 0.8" (9.9 x 6.1 x 2.0 cm)
Wt: 5.21 oz. (147.8 g)
Hardin County, Illinois, U.S.A.
Actually a very simple specimen, this piece consists of 3 clusters of intergrown Sphalerite crystals on a dolomite-covered limestone base. The largest of these clusters has dimensions of 0.9 x 0.7 x 0.6" (2.3 x 1.8 x 1.5 cm), and consists of two crystals that are only slightly smaller than the cluster itself. The other clusters do not consist of more than 3 intergrown crystals. All of these crystals have a black color with brown highlights visible on the few tiny patches of damage. They are opaque and have a bright, adamantine luster. There are also a few very small individual crystals scattered on the host rock, which is covered with dull, dirty-white dolomite crystals. These crystals show a considerable amount of wear, but not a lot of human-induced damage. They have a curved, short bladed form and a dull luster. On one side of the specimen, a dark brown, powdery-looking substance obscures a substantial nuSPH-16
sph-16 ($ 32.00)
Hardin County, Illinois, U.S.A.
SPHALERITE specimen sph-17
$ 30.00
$ 30.00
Dims: 6.8" x 2.8" x 2.7" (15.2 x 7.1 x 6.9 cm)
Wt: 1 lb., 1.5 oz. (496 g)
Hardin County, Illinois, U.S.A.
A few dozen Sphalerite crystals rest on the dolomitic limestone host rock of this specimen. The largest crystal measures about 0.9 x 0.7 x 0.7" (2.3 x 1.8 x 1.8 cm), and though it shows considerable damage, all of the rest are in excellent condion. Their form is a complex variation of tetrahedron, and their edges show intense gradation, so it appears that their faces are highly striated. This feature is intensified by their subadamantine luster and their dark, brown-black coloration. Needless to say, the crystals are opaque to all intents and purposes. Accompanying the Sphalerites are many small, curved blades of dolomite that have a white color and a dull luster. There is also a single, pale yellow calcite crystal that is in the form of a six-sided prism with a shallow, three-sided pyramidal termination. It has a bright pearly luster and is transparent and relatively clear, though inclusions cloud a portion of it.
sph-17 ($ 30.00)
Hardin County, Illinois, U.S.A.
SPHALERITE specimen sph-19
$ 45.00
$ 45.00
Dims: 1.7" x 1.2" x 1.2" (4.3 x 3.0 x 3.0 cm)
Wt: 8.00 oz. (226.8 g)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
A rather simple specimen, this piece consists of several Sphalerites which rest on a gray shale host rock that is partially covered with tiny, colorless quartz crystals. They are generally in good condition, though several were damaged when the specimen was separated from its place of formation. The largest of these measures 0.6 x 0.6 x 0.6" (1.8 x 1.5 x 1.5 cm) and like the others, has a somewhat warped but discernable tetrahedral form. All have a deep brown color and a bright, adamantine luster, and are dimly translucent, with tiny patches of dim transparence.
sph-19 ($ 45.00)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
SPHALERITE specimen sph-20
$ 35.00
$ 35.00
Dims: 2.5" x 2.2" x 2.0" (6.4 x 5.6 x 5.1 cm)
Wt: 5.94 oz. (168.6 g)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
Another specimen from the prolific Elmwood Mine, this piece consists of a gray dolomitic limestone host rock on which rest several Sphalerite crystals. These crystals range in diameter from 0.2 - 0.8" (0.5 - 2.0 cm), and are sometimes difficult to define, as they are often heavily intergrown. Their tetrahedral forms are very warped, but only one crystal shows any sign of heavy damage. All have the deep brown color and adamantine luster that is common for material from this locality, and show patches of dim translucence/transparence under bright, halogen light. The host rock on which they rest is partially encrusted with tiny colorless quartz and white dolomite crystals.
sph-20 ($ 35.00)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
SPHALERITE specimen sph-21
$ 120.00
$ 120.00
Dims: 2.9 x 2.0 x 1.5" (7.4 x 5.1 x 3.8 cm)
Wt: 2.5 oz. (70.8 g)
Hengyang, Hunan Province, China
Essentially, only 3 Sphalerite crystals rest on the calcite-encrusted host rock of this specimen, and 2 of those are at least partly obscured. The largest of these is the most exposed, and measures 0.3" (8 mm) in diameter. All are in pristine condition, however, showing only microscopic damage, if any. Their form is warped- the smallest crystal is too heavily obscured to effectively study, but the others are obviously intergrown with their base; the largest crystal also appears to be made up of at least 3 crystals that are intensely intergrown. Their edges are still well-defined, however, and their faces are clean and possess the standard adamantine luster. All have a dark brown color and are transparent and moderately clear even under normal light, though each is considerably internally-fractured. The accompanying calcites show a lot of damage and considerable breakage- they occur in the tabular "nailhead" form and are transparent but somewhat cloudy. Hundreds of tiny quartz crystals also coat the base rock- they do not exceed 2 mm in lenSPH-21
sph-21 ($120.00)
Hengyang, Hunan Province, China
SPHALERITE specimen sph-22
$ 225.00
$ 225.00
Dims: 2.6 x 1.9 x 1.7" (6.6 x 4.8 x 4.3 cm)
Wt: 2.3 oz. (65.4 g)
Hengyang, Hunan Province, China
The drusy quartz base of this small hand specimen contains four small clusters of heavily intergrown Sphalerite crystals. All of these show some noticeable damage, and at least one is incomplete. The largest of these clusters averages 0.5" (1.3 cm) in diameter, and the others are measure about half that. All have noticeable cubic-based form, though the intergrowth of their crystals makes their exact form difficult to define; three of them appear to show evidence of twinning, however. All have a moderately dark brown coloration and an adamantine luster, and are dimly to moderately transparent, depending on their size. The drusy host rock on which they rest is made up of integrown plates of microcrystalline quartz that are covered with tiny, milky-white quartz crystals.
sph-22 ($225.00)
Hengyang, Hunan Province, China
SPHALERITE specimen sph-23
$ 25.00
$ 25.00
Dims: 1.4 x 1.3 x 1.0" (3.6 x 3.3 x 2.5 cm)
Wt: 1.37 oz. (39.0 g)
Pine Point, Northwest Territories, Canada
I have never heard of this locality before, so maybe this is a rather unusual Sphalerite specimen. It consists of dozens of heavily intergrown crystals, most of which are directionally aligned with others into parallel associations. Though it is essentially impossible to determine, I think that none of these crystals exceed 0.2" (5 cm) in diameter. Their form is also difficult to study, but appears to be tetrahedral- many of them may also show twinning. There is a substantial amount of breakage visible, but the intact Sphalerites are generally in good condition. There is no host rock present, and the specimen is hot-glued onto an acrylic base.
sph-23 ($ 25.00)
Pine Point, Northwest Territories, Canada
SPHALERITE specimen sph-24
$ 35.00
$ 35.00
Dims: 2.0 x 1.4 x 1.3" (5.1 x 3.6 x 3.3 cm)
Wt: 3.27 oz. (92.9 g)
Ballard Mine, Tri-State District, U.S.A.
Unfortunately, I am not sure if the Ballard Mine is in Illinois or Missouri, but I am pretty certain that it is one of those two mid-American states. This specimen consists of many intergrown Sphalerite crystals that range in diameter from less than 0.1" (3 mm) to 1.1" (2.8 cm). The largest crystals have the most disseminated cubic-based form, so that one cannot determine exactly what variation they retain. The smaller crystals are much better-formed, taking on the shapes of distended octahedrons. Some show evidence of twinning, and appear to have a hexagonal outline. Several of these small Sphalerites are broken, but they have a wonderful, deep brown-red coloration and exceptional clarity. When viewed under a bright halogen light, one can see that the Sphalerite that serves as the base for the accompanying chalcopyrites also has the red color, though it is much deeper and dimmer. There is also a small amount of a shale base present.
sph-24 ($ 35.00)
Ballard Mine, Tri-State District, U.S.A.
SPHALERITE specimen sph-25
$ 70.00
$ 70.00
Dims: 4.1 x 3.2 x 1.9" (10.4 x 8.1 x 4.8 cm)
Wt: 1 lb., 6.0 oz. (623 g)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
This hand specimen consists of a cluster of large, heavily-intergrown Sphalerite crystals. Their intense intergrowth makes measurement difficult, but I estimate that the largest crystals measure up to 0.8" (2.0 cm) or more along an edge. There are several spots of minor damage and a few broken crystals, but most are still intact and in good condition. This intergrowth has also severely warped their forms- though crystal form is evident, it is usually impossible to separate one crystal from another, and the tendency for Sphalerite to twin compounds this problem. All have a very dark brown color and the standard adamantine luster- their depth of color and intergrowth make only the smallest crystals visibly translucent or transparent. There are no other minerals present on the piece, and only a tiny bit of the gray limestone base rock is visible on the bottom of the cluster.
sph-25 ($ 70.00)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
SPHALERITE specimen sph-26
$ 36.00
$ 36.00
Dims: 3.4 x 2.6 x 1.5" (8.6 x 6.6 x 3.8 cm)
Wt: 12.4 oz. (352 g)
Pachapaque Mine, Ancash Department, Peru
Dozens of small, intergrown Sphalerite crystals are scattered on the surface of this hand specimen. They do not tend to exceed 0.3" (8 mm) in diameter, but are all in very good condition, as damage is sparse. Though heavily intergrown, there is definite evidence of reasonably good octahedral form, though no complete crystals are visible. All have well-defined edges and clean faces that possess the standard adamantine luster. The Sphalerites are accompanied by several other minerals, including pyrite, quartz, calcite, and bournonite. The entire specimen appears to be made up solely of these minerals.
sph-26 ($ 36.00)
Pachapaque Mine, Ancash Department, Peru
SPHALERITE specimen sph-27
$ 28.00
$ 28.00
Dims: 2.8 x 2.4 x 1.3" (7.1 x 6.1 x 3.3 cm)
Wt: 4.9 oz. (140.0 g)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
This small hand specimen contains at least 15 Sphalerite crystals. They are generally in good condition, though 4 or 5 crystals are damaged or broken. The 2 or 3 largest crystals are heavily intergrown and warped, so that the viewer cannot discern one from another. It would appear that these crystals measure at least 0.5" (1.3 cm) in diameter, however. The other crystals show good tetrahedral or octahedral form, though they too are often intergrown with each other. Several are also twinned, further adding to the confusion. Most still have well-defined edges and lightly patterned but clean faces, however, and all have the dark brown color and adamantine luster that are standard for their species. They are so dark in color that they are essentially opaque. Most of the crystals rest on a bed of crystalline dolomite, but some rest on the pale gray limestone base rock.
sph-27 ($ 28.00)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
SPHALERITE specimen sph-28
$ 26.00
$ 26.00
Dims: 3.2 x 2.1 x 1.1" (8.1 x 5.3 x 2.8 cm)
Wt: 7.8 oz. (223 g)
Huaron Mine, Ancash Department, Peru
A crust that is made up of scores of intergrown Sphalerite crystals makes up part of this small hand specimen. These crystals do not exceed 0.3" (8 mm) along any axis and are in good condition, showing damage only around the edge of the crust. Their heavy intergrowth along with intense twinning makes their cube-based forms difficult to ascertain, but they still show very well-defined edges and clean faces that possess a bright pearly luster. All have a very dark brown coloration and are essentially opaque. The Sphalerites are accompanied by several clusters of small, well-formed, colorless and transparent quartz crystals and rests on a layer of crystalline pyrite, which in turn rests on a layer of highly rounded and intergrown galena crystals.
sph-28 ($ 26.00)
Huaron Mine, Ancash Department, Peru
SPHALERITE specimen sph-29
$ 90.00
$ 90.00
Dims: 4.7 x 4.5 x 2.5" (11.9 x 11.4 x 6.4 cm)
Wt: 2 lbs., 11 oz. (1.218 kg)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
A large cluster of warped and intergrown Sphalerite crystals rests on the gray limestone base of this specimen. These crystals are generally in good condition (only a few small areas on the edge of the cluster are damaged) but are so heavily intergrown that it is almost impossible to tell where one ends and another begins. Due to intergrowth and probable twinning, their individual forms are also nearly impossible to make out. However, there are many small but straight edges and clean faces present. All have a dark brown coloration and a bright, adamantine luster, and are essentially opaque. Several small dogtooth calcites rest on the Sphalerite cluster (all but three are broken and incomplete), along with several very small fluorites. The gray host rock is made of a dolomitic limestone and has a hollow in which rest several tiny, white dolomite crystals.
sph-29 ($ 90.00)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
SPHALERITE specimen sph-30
$ 64.00
$ 64.00
Dims: 5.1 x 3.6 x 2.7" (13.0 x 9.1 x 6.9 cm)
Wt: 1 lb., 8 oz. (680 g)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
This large hand specimen consists of a cluster of large, heavily-intergrown and warped Sphalerite crystals that rest on a limestone base. Many are heavily damaged or broken, but several are intact. These crystals appear to measure up to 1.2" (3 cm) along an edge, though twinning may give them their large size. Even with their intergrowth and twinning, the larger ones still have a moderately good, though considerably warped form, with some well-defined edges and a few flat, clean faces. All have the dark brown coloration and adamantine luster that one expects in Sphalerite from this locality. They are accompanied by countless small, white dolomite crystals that coat the dolomitic limestone base.
sph-30 ($ 64.00)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
SPHALERITE specimen sph-31
$ 55.00
$ 55.00
Dims: 1.6 x 1.3 x 1.2" (4.1 x 3.3 x 3.0 cm)
Wt: 2.0 oz. (58 g)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
Two very large and rather warped Sphalerite crystals rest on the dolomitic limestone base of this piece. Each of these crystals appears to be made up of more than one crystal that are heavily intergrown with each other, and one shows definite twinning. Both are in good condition but show some minor damage, and both have a badly warped tetragonal form that appears nearly sphenoidal, with disjointed and sometimes slightly curved faces. Even so, their edges are well-defined. They have the standard dark brown coloration a bright, nearly adamantine luster, and are essentially opaque. They are accompanied by a druse of tiny, transparent quartz crystals and a few white dolomites.
sph-31 ($ 55.00)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
SPHALERITE specimen sph-32
$ 27.00
$ 27.00
Dims: 2.2 x 1.6 x 1.0" (5.6 x 4.1 x 2.5 cm)
Wt: 2.6 oz. (73 g)
Huaron Mine, Ancash Department, Peru
This small piece consists of a cluster of intergrown Sphalerites that actually makes up the base of the piece. The largest of these crystals reaches a diameter of 0.9" (2.3 cm), and is likely in the best condition, as the others are at least moderately damaged. They are all heavily intergrown, but they appear to have a good octahedral form, with well-defined edges and striated but clean faces. They have a bright pearly luster and a dark black-brown color, and are essentially opaque. The Sphalerites are accompanied by several small pyrite cubes, 5 of which are clustered together, and a few tiny quartz crystals.
sph-32 ($ 27.00)
Huaron Mine, Ancash Department, Peru
SPHALERITE specimen sph-33
$ 30.00
$ 30.00
Dims: 4.4 x 2.2 x 1.3" (11.2 x 5.6 x 3.3 cm)
Wt: 6.4 oz. (182 g)
Huaron Mine, Ancash Department, Peru
Several warped and partly-intergrown Sphalerites rest on the quartzite base of this specimen. These Sphalerites do not exceed 0.5" along any visible axis and are in generally fair condiiton, as many are broken or damaged. Their octahedral form is still well-defined in some places, though, and all have straight edges and clean faces that possess a nearly metallic luster. This luster may be caused by a thin layer of chalcopyrite that partly coats almost every Sphalerite, giving them a golden color in places. A few chalcopyrite crystals accompany them, along with many small quartz crystals, a few tiny, white calcite nodules, and a small amount of galena.
sph-33 ($ 30.00)
Huaron Mine, Ancash Department, Peru
SPHALERITE specimen sph-34
$ 27.00
$ 27.00
Dims: 3.8 x 2.5 x 1.6" (9.7 x 6.4 x 4.1 cm)
Wt: 7.49 oz. (212.5 g)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
Two adjacent Sphalerite clusters rest on the gray limestone base of this hand piece. The larger cluster is made up of several heavily-intergrown Sphalerite crystals that are in good condition and do not appear to exceed 0.5" (1.3 cm) in diameter. All show very warped tetrahedral form. The other cluster might actually be a single crystal- it has the triangular shape of a tetrahedron, though it is flattened (see the second image). All have a dark brown coloration and an adamantine luster, and show dim transparence along their edges when examined under bright light. A single, tiny violet fluorite cube rests nearby.
sph-34 ($ 27.00)
Elmwood Mine, Carthage, Smith County, Tennessee, U.S.A.
SPHALERITE specimen sph-35
$ 45.00
$ 45.00
Dims: 5.0 x 4.5 x 1.6" (12.7 x 11.4 x 4.1 cm)
Wt: 1 lb., 2.8 oz. (533 g)
Chihuahua, Mexico
This cabinet specimen consists of a few clusters of heavily-intergrown Sphalerites embedded in a white matrix that I cannot identify. These clusters are in moderately good condition, as all of them are damaged to some extent. Their form is so warped that it does not appear to be related to the isometric system. The crystals therein have the standard dark brown color and adamantine luster, and are translucent or dimly transparent along their edges. A few small fluorite cubes rest among the Sphalerites.
sph-35 ($ 45.00)
Chihuahua, Mexico
SPHALERITE specimen sph-37
$ 50.00
$ 50.00
Dims: 4.1 x 2.1 x 1.2" (10.5 x 5.2 x 3.1 cm)
Wt: 7.8 oz. (220 g)
Reynolds County, Missouri, U.S.A.
The limestone base of this specimen is coated with Sphalerite crystals over more than 50% of its surface area. Most of these crystals do not exceed 0.1" (3 mm) in diameter, but several are very large, exceeding 0.8" (2 cm) along an axis. They are generally in very good condition, and their warped tetrahedral form is quite good for their locality- some definite twinning (some of which is Spinel-Law) is also visible. All have the dark, black-brown color of their species and a bright, greasy luster. A few bits of broken calcite are also present.
sph-37 ($ 50.00)
Reynolds County, Missouri, U.S.A.
SPHALERITE specimen sph-38
$ 33.00
$ 33.00
Dims: 4.5 x 3.6 x 2.1" (11.5 x 9.1 x 5.3 cm)
Wt: 15.6 oz. (442 g)
Huaron Mine, Ancash Department, Peru
Several Sphalerite crystals and clusters rest on the quartz host rock of this specimen. The Sphalerites are in moderately good condition, as some are badly broken and mostly incomplete, but those that are intact are in excellent condition and have a highly disseminated but well-defined octahedral-based form- twinning appears to be extensive, some of it according to Spinel-Law. All have the standard black-brown coloration and bright, resinous luster, and are opaque. They are accompanied by many transparent quartz crystals and several chalcopyrites that are coated with a dark gray crust. One such chalcopyrite is surrounded by an association of Sphalerites that could almost be considered a single entity (see the second image).
sph-38 ($ 33.00)
Huaron Mine, Ancash Department, Peru
SPHALERITE specimen sph-39
$ 100.00
$ 100.00
Dims: 3.47x3.38x2.81" (8.82x8.58x7.14cm)
Wt: 22.44oz (635g)
Dalnyegorsk, Russia
This large hand specimen is mostly sphalerite by weight, and it also contains several large galena crystals, quite a bit of pyrite, and some quartz crystals. The sphalerite appears black and opaque, with an interesting branched structure and a surface growth pattern that looks like stacks of flat crystals (but it is really a single crystal). THe galena has a dull, weathered appearance, but its cubic form, stepped growth, and light gray color is distinctive. The pyrite shows two habits. The bottom half of the specimen has larger crystals in typical but distorted shapes of cubes and pyritohedrons, but the top half of the specimen has distinct sheets of tiny pyrite crystals, probably an overgrowth (or replacement) of another mineral that has since disolved.
sph-39 ($100.00)
Dalnyegorsk, Russia
SPHALERITE specimen sph-40
$ 25.00
$ 25.00
Dims: 2.58x1.98x1.78" (6.55x5.02x4.52cm)
Wt: 2.63oz (74.7g)
Hunan Province, China
This specimen has two nice sphalerite crystals (one on top, the other on bottom), plus a scattering of small ones. The sphalerite is nearly transparent. In some places, I can see into the crystal for some depth (with the aid of a loupe). The sphalerite is reddish-brown in color, and in a few places I can see a characteristic red flash in the crystal. The host rock is composed (or at least covered) with tiny white opaque prismatic quartz crystals.
sph-40 ($ 25.00)
Hunan Province, China
SPHALERITE specimen sph-41$ 40.00
Dims: 1.66x1.07x0.67" (4.21x2.73x1.69cm)
Wt: 0.97oz (27.5g)
Madan, Bulgaria
This beauty is is a rare find - it is a sphalerite specimen, but it is transparent and green! There are dozens of good crystals, intergrown with dull weathered galena crystals and tiny white quartz crystals (a cluster of which formed the attachment point for this specimen). I have never seen good, transparent sphalerite crystals before, nor green ones, so this one has two unusual features making it special. I would guess that this specimen must be zinc rich, possibly even lacking iron, so it might be nearly pure zinc sulfide.
sph-41 ($ 40.00)Madan, Bulgaria
SPHALERITE specimen sph-42
$ 50.00
$ 50.00
Dims: 1.73x1.12x0.70" (4.39x2.84x1.79cm)
Wt: 1.19oz (33.7g)
Madan, Bulgaria
This is another of those beautiful transparent green sphalerites from the Madan District in Bulgaria. Although there are inclusions and a rough surface texture to mar their clarity, these crystals are very transparent, especially in comparison to the usual opaque sphalerite that we get from Illinois and Tennessee. This specimen is also rather aesthetic, and even stands nicely on its own. The color seems to vary from more yelowish to more greeneish, with the purest green having about the same color as a Moldavite specimen. There are many small white prismatic quartz crystals present, along with some opaque black crystals that just look like more sphalerite to me.
sph-42 ($ 50.00)
Madan, Bulgaria