THE MINERAL WOLFRAMITE

  • Chemistry: (Fe, Mn)WO4, Iron manganese tungstate
  • Class: Sulfates
  • Subclass: Tungstates
  • Uses: an ore of tungsten (an important industrial element) and as a mineral specimen
  • Specimens
Wolframite is actually a series between two minerals; Huebnerite and Ferberite. Huebnerite is the Manganese rich end member while ferberite is the iron rich end member. Wolframite is the name of the series and the name applied to indistinguishable specimens and specimens intermediate between the two end members. Most specimens found in nature fall within 20 - 80% range of the series and these are termed wolframites. Only if they are more pure than 80% manganese are they called huebnerite and conversely if they are 80% iron they are called ferberite.

PHYSICAL CHARACTERISTICS:

  • Color is Black to grey or brown.
  • Luster is submetallic to resinous.
  • Transparency crystals are translucent to opaque.
  • Crystal System is monoclinic; 2/m
  • Crystal Habits include the flat, heavily modified, tabular crystals. The crystals are elongated along the c axis and are generally flattened in the a axis direction. Also as columnar aggregates and lamellar masses.
  • Cleavage is perfect in one direction parallel to the a and c axes.
  • Fracture is uneven.
  • Hardness is 4 - 4.5.
  • Specific Gravity is approximately 7.0 - 7.5 (heavy even for metallic minerals)
  • Streak is brown to black.
  • Associated Minerals are quartz, hematite, tourmalines, cassiterite, micas and pyrite.
  • Other Characteristics: crystals striated lengthwise.
  • Notable Occurrences include Nanling Range, China; southwest and Colorado, USA; Russia; Korea; England and Bolivia.
  • Best Field Indicators are crystal habit, color, density, luster and cleavage.
WOLFRAMITE specimens:
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WOLFRAMITE specimen wol-1
$ 30.00
Dims: 3" x 1" x 0.7"
Wt: 3.7oz
Kara-oba, Kazakhstan
The bulk of this specimen is composed of a portion of a large, black crystal of Wolframite that has definite crystalline striations along its length. The tip is adorned by two cubes of Pyrite, and there are a few more cubes along one side. Also included are a few small Quartz(?) crystals and what look like some tiny spheroidal aggregates of Galena- one must look closely to see them. This is one of only a few specimens of Wolframite that we have, as it is difficult to obtain.
no photo
wol-1 ($ 30.00)
Kara-oba, Kazakhstan
WOLFRAMITE specimen wol-2
$ 30.00
Dims: 3" x 2" x 1-3/4"
Wt: 7.04 oz
Little Dora, San Juan Co., Colorado, U.S.A.
On a rather large quartzite base lies a cluster of Wolframite crystals. There is not much definition in the cluster, so it is difficult to isolate individual crystals, although there are a few visible that are hiding below the main cluster. I deduce that the lack of definition is caused by damage, occurring both before and during the specimen's exhumation. The crystals seem to attain a maximum length of about 1/2" and have the dark gray color, submetallic luster, and hackly fracture that is standard for this mineral.
no photo
wol-2 ($ 30.00)
Little Dora, San Juan Co., Colorado, U.S.A.
WOLFRAMITE specimen wol-3
$ 110.00
Dims: 1.8" x 1.4" x 0.4" (4.6 x 3.6 x 1.0 cm)
Wt: 1.70 oz. (48.4 g)
Yaogangxian Mine, Cheng Zhu, Hunan Province, China
This lovely Wolframite specimen consists of a parallel association of four crystals, three of which are heavily intergrown with a much larger one. The largest crystal's dimensions make up those of the entire piece, and the crystal is actually twinned, with its twin intergrown along one of its broadest faces. The crystals show only a small amount of damage and have excellent monoclinic, bladed form and sharp edges and clean faces that show an adamantine, submetallic luster. They have a black coloration and are definitely opaque. There are a few tiny, golden metallic flashes on the surface of the crystal's base, representing an associated metallic sulfide, but there is no other identifiable material attached to the crystal. It is one of the finer crystalline Wolframite specimens that we could find.
no photo
wol-3 ($110.00)
Yaogangxian Mine, Cheng Zhu, Hunan Province, China
WOLFRAMITE specimen wol-4
$ 65.00
Dims: 1.9" x 1.5" x 0.4" (4.8 x 3.8 x 1.0 cm)
Wt: 2.51 oz. (71.2 g)
Yaogangxian Mine, Cheng Zhu, Hunan Province, China
This specimen consists of a single monoclinic, bladed Wolframite crystal that has good form and shows only a small amount of damage. Its termination tip appears to have suffered some damage that was partially healed before the crystal was mined. However, its form is very good, with well-defined edges and mostly smooth faces that show a subadamantine luster. One of the two largest faces, however, shows many crystalline growth patterns. The crystal is opaque and colored black, though there seem to be some subtle brown highlights. It would appear that the crystal broke off of its host and underwent massive healing over the break, as it shows small but bright and well-defined crystalline faces and edges, even though it is generally uneven.
no photo
wol-4 ($ 65.00)
Yaogangxian Mine, Cheng Zhu, Hunan Province, China
WOLFRAMITE specimen wol-5
$ 32.00
Dims: 1.4" x 1.1" x 0.9" (3.6 x 2.8 x 2.3 cm)
Wt: 22.4 g
Yaogangxian Mine, Cheng Zhu, Hunan Province, China
This thumbnail specimen consists of a single, nearly complete Wolframite crystal that is attached to shards of at least 3 other crystals. All have the standard black color and bright, adamantine luster that is common for this mineral The most complete crystal has dimensions of 1.1 x 0.8 x 0.1" (2.8 x 2.0 x 0.3 cm) and has good form, showing its monoclinic form and a complete, intact termination. It is broken down near where its base would be. The other crystals are less than 50% complete and show both breakage and partial healing. They are held together by what appear to be small crusts of misshapen, bladed calcites, along with tiny muscovite crystals and a dark green material that I cannot identify.
no photo
wol-5 ($ 32.00)
Yaogangxian Mine, Cheng Zhu, Hunan Province, China
WOLFRAMITE specimen wol-6
$ 135.00
Dims: 3.1" x 2.1" x 1.6" (7.9 x 5.3 x 4.1 cm)
Wt: 9.77 oz. (276.9 g)
Kara-Oba, Kazakhstan
One of the larger Wolframite specimens in our selection, this hand specimen contains at least 2 monoclinic, tabular crystals. Each of these 2 crystals appears to be made up of several smaller crystals that are intensely intergrown, but I will refer to them each as a single unit. They have dimensions of 2.4 x 1.8 x 0.3" (6.1 x 4.6 x 3.3 cm) and 2.0 x 1.2 x 0.4" (5.1 x 3.0 x 1.0 cm). The smaller crystal shows visible damage along one of its edges, but the larger is undamaged and in excellent condition. Both have a black color with some grayish highlights and show a bright, adamantine luster that is slightly metallic in some areas. Their edges are well-defined and their faces are striated but clean. Both crystals are partially engulfed by a quartz-and-pyrite base rock; both the quartz and the pyrite occur as small crystals, most of which are damaged.
no photo
wol-6 ($135.00)
Kara-Oba, Kazakhstan
WOLFRAMITE specimen wol-7
$ 50.00
Dims:2.8x2.4x1.2" (7.1x6.1x3.0 cm)
Wt: 4.7oz. (132g)
Yao Gang Xian mine, Chenzhou, China
This specimen consists of an intergrown cluster of wolframite crystals growing from a matrix of massive quartz. Several euhedral quartz crystals accompany the wolframites. The wolframite crystals are rudely terminated, but exhibit excellent vertical striations typical for this species. The largest wolframite crystal measures 2.4" (6.1 cm) in length, and the largest quartz crystal measures 1.5" (3.8 cm) in length. This specimen shows only minor damage. One of the quartz crystals is penetrated by a wolframite crystal for an interesting optical effect.
no photo
wol-7 ($ 50.00)
Yao Gang Xian mine, Chenzhou, China
WOLFRAMITE specimen wol-8
$ 75.00
Dims:2.0x1.6x2.0" (5.1x4.1x2.0 cm)
Wt: 2.8oz. (80g)
Yao Gang Xian Mine, Chen Zhou, Hunan province, China
This specimen consists of a cluster of wolframite crystals with no matrix. These wolframites have basal terminations. The largest crystal measures 1.3x1.1x0.1" (3.3x2.8x0.3cm). there is a small amount of quartz on the sides of the specimen. There is only a couple of tiny chips or nicks on this piece.
no photo
wol-8 ($ 75.00)
Yao Gang Xian Mine, Chen Zhou, Hunan province, China
WOLFRAMITE specimen wol-9
$ 75.00
Dims: 1.97x1.18x0.83" (5.0x3.0x2.1cm)
Wt: 3.48oz (98.4g)
Yao Gang Xian Mine, Chen Zhou, Hunan Province, China
This is a nice wolframite specimen, dense, black with a metallic luster, and boasting the striated crystals and typical shapes and terminations of the specie. It also has at least 3 other minerals present, most notably a very nice cubic fluorite crystal perched nicely towards the top of the wolframite, and also a thin druze of arsenopyrite on the opposite side, and a mineral I have not identified is wedged into the wolframite. It is off-white, translucent, and looks like it may be a member of the mica family. The fluorite is transparent and nearly colorless but with a hint of blue, and it has a dusting of black specs dulling its luster.
no photo
wol-9 ($ 75.00)
Yao Gang Xian Mine, Chen Zhou, Hunan Province, China
 

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