THE MINERAL PYRRHOTITE
- Chemistry: Fe1-xS (x=0 to x=0.2), Iron Sulfide
- Class: Sulfides and Sulfosalts
- Group: Nickeline
- Uses: mineral specimens and as an ore of sulfur and iron.
Specimens
Secondly, it has two symmetries. While this should indicate that there are two minerals and not one, in the case of pyrrhotite, mineralogists have made an exception. When pyrrhotite is low in sulfur and the formula is closer to true FeS, then the structure is hexagonal. But when it is high in sulfur, the structure is monoclinic. Clearly two different symmetries, two different formulae; therefore, two different minerals . . . except, that in natural pyrrhotite crystals both phases are present in the same crystal. If you are a purist, you can think of a pyrrhotite crystal as an assemblage of two minerals, but most minerologists treat it as one.
Thirdly, pyrrhotite is magnetic or at least weakly so.
It is the next most common magnetic mineral to magnetite.
Although not all specimens will show great evidence of magnetism if any, some will attract a paperclip or needle suspended from a string or move the needle of a compass.
Massive pyrrhotite is common and magnetism is sometimes the only way to distinguish it from other brassy colored sulfides such as chalcopyrite, pyrite, pentlandite or
PHYSICAL CHARACTERISTICS:
- Color is bronze.
- Luster is metallic.
- Transparency crystals are opaque.
- Crystal System hexagonal, 6/m2/m2/m and monoclinic; 2/m
- Crystal Habits: tabular or prismatic in hexagonal prisms with a pinacoidal termination, but mostly massive rock forming beds with other sulfides.
- Cleavage none but there is a strong parting tendency.
- Fracture is uneven
- Hardness is 3.5-4.5
- Specific Gravity is 4.6
- Streak gray-black
- Associated Minerals pentlandite, quartz, ankerite, pyrite and other sulfides.
- Other Characteristics: weakly magnetic, prism faces striated parallel to pinacoid faces and color will darken with exposure to light.
- Notable Occurances Sudbury, Ontario; Ducktown, Tennessee; Chihuahua, Mexico; Russia; Germany and Brazil.
- Best Field Indicators magnetism, crystal habit, hardness and color.
 Amethyst Galleries' Mineral Gallery MINERALS |
PYRRHOTITE specimen prr-1
$ 45.00
$ 45.00
Dims: 2-5/8" x 2-1/2" x 2"
Wt: 12.2 oz
Dalnegorsk, Russia
A large number of hexagonal tabular crystals constitute this excellent specimen. Though lacking smooth edges and faces and a well-developed crystal form, the staggering of the platelets that are stacked together are extremely attractive. Some of the faces show irridescent discoloration akin to that of an oxide coating. There are a few crystals of Marcasite attached to the bulk of Pyrrhotite, but almost no other crystal or matrix material. This is a very intricate piece when one puts it under magnification.
prr-1 ($ 45.00)
Dalnegorsk, Russia
PYRRHOTITE specimen prr-2
$ 30.00
$ 30.00
Dims: 2-3/4" x 2-1/8" x 1"
Wt: 4.8 oz
Dalnegorsk, Russia
Some of the largest crystals of Pyrrhotite that I've seen comprise this "Little Russian." They are platy hexagonal tablets, intersecting and well-formed, with some of them measuring up to an inch or more in diameter. One of the two other minerals present seems to be Galena or possibly (though doubtful) Bournonite, which shows up as a few gray, semicrystalline "blotches." On the specimen's reverse, there rests one lonely, slender Quartz crystal... quite the attractive piece from Mother Russia!
prr-2 ($ 30.00)
Dalnegorsk, Russia
PYRRHOTITE specimen prr-4
$ 20.00
$ 20.00
Dims: 2-1/8" x 2-1/8" x 1-1/4"
Wt: 4.49 oz
Mina El Potosi, Santa Eulalia, Chihuahua, Mexico
The bulk of this specimen is made up of several crystals of Pyrrhotite, the iron sulfide known for its slight magnetism. The crystals have the classic brown-gold color, submetallic luster, and platy, hexagonal shape with basal terminations that Pyrrhotite so often has. The largest crystal on the piece, measuring about 1 inch by 1 inch, is half missing. It either grew that way or it did some substantial healing after the break, because its luster at the "missing edge" is similar to that of the complete prism faces. The other crystals erupt only partially out of the matrix, so their hexagonal form is not easy to see, but what is visible is complete, with little damage. The matrix from which they rise is made up of small crystals of Pyrrhotite mixed with even smaller crystals of sphalerite and arsenopyrite, along with a few tiny dogtooth calcite crystals.
prr-4 ($ 20.00)
Mina El Potosi, Santa Eulalia, Chihuahua, Mexico
PYRRHOTITE specimen prr-5
$ 35.00
$ 35.00
Dims: 4.0" x 3.6" x 3.0" (10.2 x 9.1 x 7.6 cm)
Wt: 2 lbs., 6.3 oz. (1.086 kg)
Santa Eulalia, Chihuahua, Mexico
One of the larger Pyrrhotite specimens in our stock, this large piece contains at least 15 hexagonal prismatic crystals with flat, basal terminations or parting planes. The largest of these measures almost 1.0" (2.5 cm) in diameter, and like the other crystals, has very good form and little damage. All of the crystals have a rusty, dull golden color and a rather dim metallic luster, and are, of course, opaque. Their basal faces are lined with rather unusual patterns that have hexagonal, geometric tendencies. Scattered among the Pyrrhotites are crusts of calcite or dolomite that are slightly rust-stained and lovely, tiny, transparent fluorite crystals in the form of cubes whose edges and corners are truncated by small secondary faces. All of this rests on a host rock that I think is made up of limestone. It is an appropriate specimen for the collector who wants several easily visible Pyrrhotite crystals.
prr-5 ($ 35.00)
Santa Eulalia, Chihuahua, Mexico
PYRRHOTITE specimen prr-6
$ 42.00
$ 42.00
Dims: 2.1 x 1.7 x 1.2" (5.3 x 4.3 x 3.0 cm)
Wt: 3.96 oz. (112.2 g)
Santa Eulalia, Chihuahua, Mexico
This small hand specimen consists of a cluster of hexagonal Pyrrhotite crystals that are partly intergrown. They make up most of the specimen's mass and do not exceed dimensions of 1.3 x 1.0 x 0.7" (3.3 x 2.5 x 1.8 cm). Though there is a small amount of visible damage, the crystals are generally in excellent condition and have a good hexagonal tabular form, with well-defined edges and clean faces that possess a dull, metallic luster. The crystals have a moderately dark reddish-brown coloration and, like most metallic sulfides, are opaque. Small crystals of at least 3 other sulfide minerals are partly embedded in the Pyrrhotites. One of these is pyrite, and the others appear to be sphalerite and galena. All show some vestiges of their respective forms, though their intergrowth makes them rather difficult to study in some areas. There is no host rock present on the piece.
prr-6 ($ 42.00)
Santa Eulalia, Chihuahua, Mexico
PYRRHOTITE specimen prr-7
$ 105.00
$ 105.00
Dims: 3.0 x 2.9 x 1.8" (7.6 x 7.4 x 4.6 cm)
Wt: 10.2 oz. (290 g)
Dalnegorsk, Russia
This small hand specimen consists of a rather odd-looking Pyrrhotite formation that is accompanied by quartz and other sulfides. The formation appears to consist of several hexagonal Pyrrhotite "books" that formed very near to each other, and so became heavily intergrown as they grew. They still have noticeable hexagonal form, however, and the formation is generally in very good condition, as there is only a small amount of damage visible. It has the standard deep golden, almost brown coloration and dull metallic to submetallic luster that are standard for this mineral. Accompanying the Pyrrhotite are many hexagonal prismatic quartz crystals that form a thin crust. These crystals do not exceed 0.7" (1.8 cm) in length and are generally in very good condition, though a few are noticeably damaged. Resting on the quartz and adjacent to the Pyrrhotite are 4 galena and several chalcopyrite crystals. The galenas occur in what appears to be a cubo-octahedral form, but the fact that they are heavily warped makes this difficult to determine. They have the standard dark silver-gray coloration and a metallic luster that is brighter than that I usually see on undamaged crystals. The chalcopyrites are heavily intergrown and obscured by the galena and quartz, but appear to have a sphenoidal form. They have the standard deep golden coloration and metallic luster.
prr-7 ($105.00)
Dalnegorsk, Russia
PYRRHOTITE specimen prr-8
$ 105.00
$ 105.00
Dims: 3.3 x 2.5 x 1.4" (8.4 x 6.4 x 2.6 cm)
Wt: 14.4 oz. (409 g)
Dalnegorsk, Russia
A large, incomplete hexagonal Pyrrhotite "book" makes up most of the mass of this hand specimen. It shows considerable damage, but I believe that much of this occurred prior to mining, as much of the surface seems to be slightly healed. Otherwise, the Pyrrhotite has excellent form, with well-defined edges and clean faces that possess a slightly dull metallic luster. It has the classic deep golden-brown coloration of this material. Attached to the crystal is a small mass of galena that has crystalline tendencies, but is quite malformed. A small portion of the Pyrrhotite's surface area is covered by a druse of tiny quartz crystals that have a milky-white coloration.
prr-8 ($105.00)
Dalnegorsk, Russia
PYRRHOTITE specimen prr-9
$ 62.00
$ 62.00
Dims: 1.3 x 1.1 x 0.5" (3.3 x 2.8 x 1.3 cm)
Wt: 21.4 g w/ specimen box
Verkhnee Mine, Dalnegorsk, Primorskiy Kray, Russia
At least 20 hexagonal tabular Pyrrhotite crystals make up this thumbnail specimen. These crystals are generally in very good condition. Some of them are obviously incomplete, but I find it strange that their breakage surfaces do not appear to be either fresh or rough- they may have broken and healed prior to mining. All have excellent form, with well-defined edges and slightly concave but clean faces that possess a dull metallic luster. Their color ranges from a pale, dull gold to dark brown, and there are areas which show a blue iridescence due to some type of coating. There appears to be a dull white calcitic crust coating a small portion of the specimen, but there is no host or base rock. It is glued into a plastic specimen box.
prr-9 ($ 62.00)
Verkhnee Mine, Dalnegorsk, Primorskiy Kray, Russia
PYRRHOTITE specimen prr-10
$ 100.00
$ 100.00
Dims: 2.8 x 2.0 x 1.7" (7.0 x 5.1 x 4.3 cm)
Wt: 7.5 oz. (213 g)
Trepca, Kosovo, Yugoslavia
Several intersecting "books" of rather compact Pyrrhotite blades make up this small cabinet specimen. The largest of these books has dimensions of 2.6 x 1.7 x 0.9" (6.6 x 4.3 x 2.3 cm), and the rest are less than half its size. Each "book" shows light damage on its prism faces and has excellent apparent hexagonal form- they look like muscovite books. All have the brown-gold color and dull metallic luster that are common for the specie. Several rust-coated calcite tablets and a few broken quartz crystals are present.
prr-10 ($100.00)
Trepca, Kosovo, Yugoslavia
PYRRHOTITE specimen prr-12
$ 84.00
$ 84.00
Dims: 3.4 x 2.5 x 1.8" (8.6 x 6.4 x 4.6 cm)
Wt: 11.1 oz. (315 g)
Daln'egorsk, Primorskiy Kray, Russia
This cabinet specimen consists of a cluster of intergrown Pyrrhotite blades that serve as a base for a few other minerals. These blades reach 1.3" (3.3 cm) or greater in diameter and are generally in excellent condition, showing almost no fresh damage. Their hexagonal form is rather warped due to intergroth but still good, and they have the classic dull golden color and metallic luster of their specie. A druse of tiny, brown quartz crystals coats the Pyrrhotite, as well as a few white calcite blades. Also resting atop the Pyrrotite are at least 7 black sphalerites that reach 0.8" (2 cm) in diameter. They are in excellent condition and have excellent cubic form, showing a complex variation of the tetrahedron.
prr-12 ($ 84.00)
Daln'egorsk, Primorskiy Kray, Russia
PYRRHOTITE specimen prr-11
$ 84.00
$ 84.00
Dims: 6.5 x 4.8 x 3.1" (16.5 x 12.1 x 8.0 cm)
Wt: 4 lbs., 6.3 oz. (1.993 Kg)
Santa Eulalia, Chihuahua, Mexico
Several hexagonal Pyrrhotite crystals are embedded in the quartz/sulfide base of this display specimen. These crystals are generally in good condition- a few are damaged- and reach diameters of about 1". None are more than 50% complete due to their intergrowth with the base, but they do have very good hexagonal tabular form. They possess the classic dull golden color and metallic luster of their specie, and are accompanied by hundreds of tiny white quartz crystals and almost botryoidal formations of what appear to be tiny muscovites. The base is made up of both quartz and varying metallic sulfides, and is interestingly layered in some places.
prr-11 ($ 84.00)
Santa Eulalia, Chihuahua, Mexico
PYRRHOTITE specimen prr-13
$ 25.00
$ 25.00
Dims:1.2x1.1x0.6" (3.0x2.8x1.5 cm)
Wt: 0.9oz. (26g)
Nikolaevskiy Mine, Dal'Negorsk, Primorskiy Kray, Russia
This specimen consists of a complexly intergrown crystal of the mineral pyrrhotite, with no matrix. There is a thin vein and crust of tiny quartz crystals associated with this specimen. When a loupe is used, a fascinating view is seen on this specimen. This specimen is undamaged-excellent!
prr-13 ($ 25.00)
Nikolaevskiy Mine, Dal'Negorsk, Primorskiy Kray, Russia
PYRRHOTITE specimen prr-14
$ 45.00
$ 45.00
Dims:1.5x1.1x1.0" (3.8x2.8x2.5 cm)
Wt: 0.8oz. (25g)
Nikolaevskiy Mine, Dal'Negorsk, Russia
This specimen is an excellent extended crystal of pyrrhotite, with no matrix present. There is a large central tabular crystal, and smaller tabular crystals are stacked in "books" on either side. This is an extremely aesthetic little specimen. There are also a couple of tiny quartz crystals growing on the edges of the pyrrhotite. There is no damage to this specimen.
prr-14 ($ 45.00)
Nikolaevskiy Mine, Dal'Negorsk, Russia
PYRRHOTITE specimen prr-15
$ 60.00
$ 60.00
Dims:3.4x2.3x2.0" (8.6x5.8x5.1 cm)
Wt: 11.1oz. (314g)
Santa Eulalia, Chihuahua, Mexico
This specimen consists of an intergrown cluster of pyrrhotite crystals with a minor amount of calcite and quartz. These pyrrhotites show excellent hexagonal form, and horizontal striation that is typical to this species. The largest pyrrhotite crystal measures 1.7" (4.3cm) in length. Except for the bottom of the specimen where it was broken from the matrix, this specimen shows only minor damage-this being to one of the smaller crystals on the end.
prr-15 ($ 60.00)
Santa Eulalia, Chihuahua, Mexico
PYRRHOTITE specimen prr-16
$ 270.00
$ 270.00
Dims: 4.50x3.28x3.03" (11.43x8.33x7.70cm)
Wt: 19.29oz (546g)
Dalnyegorsk, Russia
While this specimen has more than a half-dozen pyrrhotite crystals, the largest one really makes this specimen. Perched on a matrix of intergrown prismatic quartz crystals is a single, large (3cm) pyrrhotite crystal with excellent form of a flat elongated hexagonal crystal on its side (with several sub-crystals adding to its aesthetics). It has excellent color and luster, with a slight irridescent tarnish that mirrors the crystal's hexagonal outline.
prr-16 ($270.00)
Dalnyegorsk, Russia
PYRRHOTITE specimen prr-17$ 150.00
Dims: 4.13x3.06x2.40" (10.48x7.78x6.11cm)
Wt: 19.72oz (558g)
Dalnyegorsk, Russia
This is an exceptional pyrrhotite specimen. It is perched beautifully on a base rock of pyrrhotite, quartz, and something black, which is coated with thousands of tiny prismatic white quartz crystals and lustrous hexagonal crystals of an opaque black mineral whose crystals are large enough for study and while it looks somewhat like sphalerite, I cannot be certain.
prr-17 ($150.00)Dalnyegorsk, Russia
PYRRHOTITE specimen prr-18
$ 30.00
$ 30.00
Dims: 1.87x1.32x0.82oz (4.74x3.36x2.08cm)
Wt: 2.32oz (65.7g)
Dalnyegorsk, Russia
Most of the mass of this specimen is a single crystal of pyrrhotite. It has excellent color and luster, and it has an interesting growth pattern resulting in hundreds of stepped faces. There is no host rock, although this large crystal is sort of perched upon a cluster of small pyrrhotite crystals. There is also a druze of small crystals which may be calcite or dolomite, plus some others that I don't recognize. There is very little damage to this piece, although one tiny ding on the edge reflects a silvery highlight instead of brassy, making it noticeable in spite of it measuring less than a millimeter in diameter.
prr-18 ($ 30.00)
Dalnyegorsk, Russia
PYRRHOTITE specimen prr-19
$ 35.00
$ 35.00
Dims: 1.45x1.07x1.01" (3.67x2.72x2.57cm)
Wt: 1.80oz (51.0g)
Dalnegorsk, Russia
This appears to be a single crystal of pyrrhotite, with a highly distorted but clearly hexagonal shape, a characteristic bronze color, and a complex stepped growth pattern. A loupe reveals that the specimen has a tarnish that is gray on the sides of the crystal but multicolored on the ends (but rather subtle).
prr-19 ($ 35.00)
Dalnegorsk, Russia