THE MINERAL BISMUTH

  • Chemistry: Bi, Elemental bismuth
  • Class: Elements
  • Group: Arsenic
  • Uses: An ore of bismuth and as mineral specimens.
  • Specimens

Bismuth is rarely found in nature in its elemental form. Of growing interest in rock shops, however, are laboratory-grown bismuth crystals. These crystals, while not natural, are nonetheless very interesting to the mineral hobbyist and to others. The unique look that these clusters offer is really indescribable. Its color consisits of iridescent metallic yellow, blue and green hues.

Of interest to hobbyists are the pseudocubic "hopper" crystals that are always present on the laboratory produced specimens, they are not seen in but only the rarest of natural crystals. Hopper crystals are a unique crystallographic curiosity Just the edges extend outward from the center of the crystal leaving hollow stairstep faces between these edges. The hopper crystals form due to the disparity of growth rates between the crystal edges and the crystal faces.

PHYSICAL CHARACTERISTICS:

  • Color is silver white often with a multi-colored iridescent tarnish.
  • Luster is metallic.
  • Transparency: Crystals are opaque.
  • Crystal System is trigonal; bar 3 2/m
  • Crystal Habits include mostly massive foliated forms in natural specimens, although there do exist some well formed natural crystals they are rather scarce. Laboratory grown crystals display trigonal hopper crystals that appear pseudocubic.
  • Cleavage is perfect in one direction (basal)
  • Fracture is uneven or jagged.
  • Hardness is 2 - 2.5
  • Specific Gravity is 9.7 - 9.8 (unusually heavy even for metallic minerals)
  • Streak is silver to white.
  • Other Characteristics: striations on cleavage surfaces.
  • Associated Minerals include bismuthinite and ores of cobalt and silver found in hydrothermal veins such as cobaltite and acanthite.
  • Notable Natural Occurrences include Australia; San Baldomero and La Paz, Bolivia; Devon, England; Germany and South Dakota, Colorado and California, USA.
  • Best Field Indicators are tarnish, density and cleavage. Hopper crystals in laboratory specimens are unmistakable.
BISMUTH specimens:
(hover for more info)
BISMUTH specimen bis-1
$ 45.00
Dims: 2"x2"x1-1/4"
Wt: 5.4 oz
West Germany (lab grown)
Smaller examples of this store are especially popular with children at our gift shop in Dayton, OH- this specimen is a bit more "adult" in size and price. Large, pseudo-cubic "hopper" crystals of this colorful submetallic element constitute this entire specimen. They are held together by a thick crust at their base, from which they grew. Maybe this item is not suitable for some of our "Mineralogically Correct" clientele, but there may be someone out there who would like to amass a collection of samples of the elements!
no photo
bis-1 ($ 45.00)
West Germany (lab grown)
BISMUTH specimen bis-2
$ 195.00
Dims: 2.2" x 1.8" x 1.5"(5.6 x 4.6 x 3.8 cm)
Wt: 5.55 oz.(157.4 g)
Svornost Mine, Jachymov, northwestern Bohemia, Czech Republic
This specimen is officially labeled "Native Bismuth in skutterudite", implying a challenge as far as isolating the Bismuth is concerned. However, I don't believe that it is all that difficult. The skutterudite apppears as a very light-gray material with a bright metallic luster, whereas the bismuth appears tarnished and has a bit more of a reddish coloration. Though no definite crystals are visible, there are noticeable "faces" in the mass, implying uniformities that are related to the minerals' crystal structures. Needless to say, this material makes up most of the specimen's mass. It rests on a bed of what appears to be calcite that has a pinkish tinge, likely due to included cobalt. The calcite occurs in the form of small rhombohedral crystals. This is certainly an odd piece, and supposedly collected sometime in the 1920's.
no photo
bis-2 ($195.00)
Svornost Mine, Jachymov, northwestern Bohemia, Czech Republic
BISMUTH specimen bis-3
$ 200.00
Dims: 1.0" x 1.0" x 0.5"(2.5 x 2.5 x 1.3 cm)
Wt: 24.8 g
Johanngeorgenstadt, Germany
I thought that we would never be able to find a specimen of natural, crystalline Bismuth, but here is one! On one side of the specimen, it appears to consist of two trigonal prismatic crystals that intersect each other at about a 50- to 60-degree angle. Though they are incomplete and their exact form cannot be determined, it is definitely a crystalline form. The other side of the specimen is a mish-mosh of smaller crystal faces, some of which appear as if they can come apart in thick, micaceous layers. It has a metallic luster and a white, silvery color that is slightly tarnished, giving it a very faint pinkish-brown tinge. This specimen pleases me greatly!
no photo
bis-3 ($200.00)
Johanngeorgenstadt, Germany
BISMUTH specimen bis-4
$ 225.00
Dims: 2.0" x 1.4" x 0.9" (5.1 x 3.6 x 2.3 cm)
Wt: 3.30 oz. (93.6 g)
Wolfram Camp Mine, Queensland, Australia
I was amazed to see this specimen! It is easily the largest piece of crystalline Bismuth that I have ever seen. Though there are no complete crystals present, it consists of at least 3 that are intergrown. They have a moderate gray coloration and a very dull metallic luster, except on 3 spots of considerable damage. These damaged areas show patches of bright, silvery color with a bright metallic luster, and definitely crystalline fracture surfaces that almost appear to be cleavage planes(?). It is quite a dense little specimen, too. There is no host rock or other material present.
no photo
bis-4 ($225.00)
Wolfram Camp Mine, Queensland, Australia
BISMUTH specimen bis-5
$ 25.00
Dims: 2.1 x 1.1 x 1.0 " (5.3 x 2.8 x 2.5 cm)
Wt: 27.9 g
grown in Germany
This small but very colorful specimen consists of artificially-made cluster of intergrown Bismuth crystals. These crystals show excellent trigonal, pseudocubic form with intense "hoppering", wherein the crystals' edges have grown much more than the centers of their faces. All have a metallic luster and a variety of colors. Needless to say, there is no host rock!
no photo
bis-5 ($ 25.00)
grown in Germany
BISMUTH specimen bis-6
$ 25.00
Dims: 1.6 x 1.1 x 0.8" (4.1 x 2.8 x 2.0 cm)
Wt: 22.2 g
grown in Germany
This thumbnail specimen consists of an interesting formation of intergrown, pseudocubic Bismuth crystals. These crystals have been grown in a laboratory setting, and so are in excellent condition and show exceptional form- each is in the form of a "hopper crystal", a shape that occurs when the edges of a crystal grow more quickly than the faces do. There is a very thin oxide coating on the specimen, giving it a beautiful, colorful iridescence. Otherwise, the metal has a silvery-white coloration and a metallic luster. There is no host rock present, of course.
no photo
bis-6 ($ 25.00)
grown in Germany
BISMUTH specimen bis-7
$ 150.00
Dims: 2.1 x 1.7 x 1.1" (5.3 x 4.3 x 2.8 cm)
Wt: 5.9 oz. (168 g)
Armidale, New South Wales, Australia
A chunk of obviously crystalline native Bismuth comprises this hand specimen. The Bismuth has little in the way of visible fresh damage, and though it shows many definite crystalline tendencies and is almost completely covered with definable faces, no single crystals can be isolated. The Bismuth has a rather dark silvery-gray color and a dull metallic luster. There is no base or host rock present.
no photo
bis-7 ($150.00)
Armidale, New South Wales, Australia
BISMUTH specimen bis-8
$ 36.00
Dims: 0.9 x 0.7 x 0.6" (2.2 x 1.8 x 1.6 cm)
Wt: 9 g
Hammerburg, Schlema, Saxony, Germany
This very small piece consists of an infusion of disseminated Bismuth crystals and granules in what appears to be a broken quartz matrix. Under 10x magnification, one can see many tiny pseudocubic crystals- such crystals are not uncommon in synthesized Bismuth crystals, but I do not know the frequency of their natural occurrence. All have a moderately pale silvery-gray color and a metallic luster. The specimen is affixed inside a plastic specimen box with a removable putty.
no photo
bis-8 ($ 36.00)
Hammerburg, Schlema, Saxony, Germany
BISMUTH specimen bis-9
$ 25.00
Dims: 1.7 x 1.0 x 0.9" (4.3 x 2.4 x 2.3 cm)
Wt: 2.0 oz. (58 g)
Stavoren, Transvaal, Germany
A rough chunk of native Bismuth comprises this specimen. The Bismuth seems to have some crystalline tendencies, but shows no definite form. The metal has the standard silvery-gray color and metallic luster of its specie, though some areas seem to have undergone some oxidation. There is also a small amount of quartz interspersed.
no photo
bis-9 ($ 25.00)
Stavoren, Transvaal, Germany
BISMUTH specimen bis-10
$ 25.00
Dims: 3.0 x 2.2 x 1.4" (7.6 x 5.5 x 3.5 cm)
Wt: 5.3 oz. (149 g)
Old 25 Mine, Kingsgate, New South Wales, Australia
This rather odd hand specimen consists of small bits of massive Bismuth and crystalline bismuthinite and molybdenite that are trapped in a quartz matrix. The Bismuth is rather easy to see, as it has a rather bright silvery-gray color and a bright metallic luster- the other minerals are somewhat difficult to discern from each other, as their darker gray colors and duller metallic lusters are similar.
no photo
bis-10 ($ 25.00)
Old 25 Mine, Kingsgate, New South Wales, Australia
BISMUTH specimen bis-11
$ 90.00
Dims:3.6x2.4x2.0" (9.1x6.1x5.1 cm)
Wt: 18.8oz. (532g)
Victoria Mine, Dolly Varden District, Elko cty., Nevada
Long, striated crystals of bismuth share the matrix of this specimen with quartz, pyrite, and chalcopyrite. The longest bismuth crystal reaches 1.2" (3.0cm). This is an excellent cabinet-size specimen of this native element. There is no damage to this specimen.
no photo
bis-11 ($ 90.00)
Victoria Mine, Dolly Varden District, Elko cty., Nevada
BISMUTH specimen bis-12
$ 80.00
Dims:0.7x0.6x0.2" (1.8x1.5x0.5 cm)
Wt: 0.5oz. (14g)w/box
Llallagua, Bolivia
This is an excellent cluster of native bismuth crystals perched on a small amount of matrix material. These crystals are very sharp and distinct-a true pleasure to examine. The trigonal form is demonstrated very well. There is no damage visible on this specimen. It is mounted in a plastic "perky" box.
no photo
bis-12 ($ 80.00)
Llallagua, Bolivia
BISMUTH specimen bis-13
$ 38.00
Dims: 0.9x0.8x0.7" (2.3x2.1x1.9 cm)
Wt: 1.5 oz. (41.0g)
Rio Vilace, Dept. La Paz, Bolivia
Although this specimen of natural native bismuth does not show any outward crystal faces, there is abundant evidence of crystal form in the exposed cleavage faces, plus hints of trigonal structure in the outside surface of the nugget. It looks like this specimen was a stream tumbled nugget which was broken open to expose the inner crystals. The cleavage and fracture surfaces are excellent and have a bright metallic luster, while the weathered outer surface is dull. One interesting fact - the outside has a dozen or so pits, each of which is lined with a light brown mineral and contains a clear crystal which I suspect is a calcite, although the crystals are rounded and distorted enough that I can't tell for sure.
no photo
bis-13 ($ 38.00)
Rio Vilace, Dept. La Paz, Bolivia
BISMUTH specimen bis-14
$ 60.00
Dims: 1.5x0.63x0.35" (3.9x1.9x0.9 cm)
Wt: 0.87 oz. (24.7g)
Rio Vilace, Dept. La Paz, Bolivia
This is a natural specimen of bismuth. It looks like it has been weathered, perhaps stream tumbled to a small degree, and there is no indication of crystal form. The bismuth has several fragments of quartz crystals embedded in it on all sides - perhaps the bismuth filled a pocket that contained these crystals. This specimen has a nice "heft", as bismuth is quite dense.
no photo
bis-14 ($ 60.00)
Rio Vilace, Dept. La Paz, Bolivia
BISMUTH specimen bis-15
$ 29.00
Dims: 1.5x0.9x0.6" (3.9x2.3x1.6 cm)
Wt: 1.45 oz. (42.9g)
Rio Vilace, Dept. La Paz, Bolivia
This specimen is mostly a mass of native bismuth. It has a slightly tumbled appearance, and the ends appear to have weathered to a oxide, but it may jsut be an accessory mineral. In some protected crevices are tiny crystals of some golden mineral, such as pyrite or possibly even bismuthinite. While the bismuth shows no hint of crystal structure, it does have a slightly layered appearance.
no photo
bis-15 ($ 29.00)
Rio Vilace, Dept. La Paz, Bolivia
BISMUTH specimen bis-16
$ 25.00
Dims: 1.2x0.9x0.6" (3.0x2.4x1.5cm)
Wt: 0.79 oz. (22.3g)
Rio Vilace, Dept. La Paz, Bolivia
This is a nugget of native bismuth. It has a weathered, slightly tumbled appearance. The core of the specimen is a porous, black mineral somewhat looking like goethite. Perhaps it is an oxide of bismuth. There is also a reddish-brown mineral (perhaps limonite), and some tiny crystals that may be calcite. There are also several thin, crystalline crusts of chalcopyrite. As the elemental bismuth appears on the outside of the black core, and the transition between them is smooth, I suspect they are related (and one is an alteration product of the other).
no photo
bis-16 ($ 25.00)
Rio Vilace, Dept. La Paz, Bolivia
BISMUTH specimen bis-17
$ 60.00
Dims: 0.63x0.37x0.31" (1.61x0.93x0.78cm)
Wt: 5.30ct (1.06g)
Wipper vein, NE 186 Mine, Albereda, Saxony, Germany
This is a rare specimen - native crystals of bismuth. The specimen has dozens of intergrown crystals, some of which are modified cubes or octahedrons, but most of which are thin parallel plates coated with tiny crystals of something dark and fine quartz crystals. The specimen is very light - much of the volume must be air. Now for the confusing part - The cubic-octahedral silvery crystals look like bismuth crystals. The dull brassy (weathered) plates also look like bismuth I have seen. But it is not likely that both are. I suspect that one of these is something else. Perhaps the brassy stuff is chalcopyrite, or perhaps the silvery stuff is skutterudite. I suspect the latter, as we have had specimens looking very much like the thin brassy pages in the bulk of this specimen (just not from this location).
no photo
bis-17 ($ 60.00)
Wipper vein, NE 186 Mine, Albereda, Saxony, Germany

 


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