THE MINERAL CYLINDRITE
- Chemistry: FePb3Sn4Sb2S14, Iron Lead Tin Antimony Sulfide
- Class: Sulfides
- Subclass: Sulfosalts
- Uses: Mineral specimens and as a very minor ore of lead and tin.
Specimens
Cylindrite is a most unusual sulfide mineral. It has an extremely unique crystal habit- one so unique that it pretty much corners the market on this crystal habit. Cylindrite as its name implies, forms cylindrical crystals. The crystals are actually coiled sheets that give the appearance of having been rolled into tubes or cylinders. Under pressure the sheets, often described as leaves or shells, become uncoiled. The only crystal habit similar to this is at a microscopic level and occurs with chlorite and serpentine and results in tubes resembling hairs. Cylindrite's tubes are visible to the eye, but may require a hand lense or loop to see the fine detail. With this unusual crystal habit, cylindrite is a must have for someone who likes one-of-a-kind forms.
PHYSICAL CHARACTERISTICS:
- Color is iron black to gray.
- Luster is metallic.
- Transparency: Crystals are opaque.
- Crystal System is trigonal, but is in dispute.
- Crystal Habit is extremely unique. Crystals form small wrapped cylinders (hense the name) that look like tubes or rolls of metallic cloth. Also found massive.
- Cleavage: None.
- Fracture: Conchoidal to uneven.
- Hardness is 2.5
- Specific Gravity is 5.4 - 5.5 (somewhat heavier than average for metallic minerals)
- Streak is black.
- Other Characteristics: Under pressure, cylinders will separate into curved shells or leaves.
- Associated Minerals include
pyrite,
sphalerite,
cassiterite,
teallite and franckeite. - Notable Occurrences are limited to Mina Santa Cruz, Poopo, Oruro, Bolivia and a few other tin sulfide deposits.
- Best Field Indicators include the very unusual crystal habit as well as the locality, softness, color and luster.
 Amethyst Galleries' Mineral Gallery MINERALS |
CYLINDRITE specimen cyl-1
$ 100.00
$ 100.00
Dims: 2.6 x 1.6 x 1.2" (6.6 x 4.1 x 3.0 cm)
Wt: 2.73 oz. (77.4 g)
Poopo, Bolivia
This large thumbnail specimen consists of countless intergrown Cylindrite crystals. These crystals are in moderately good condition and achieve lengths of up to 1.1" (2.8 cm). All have the standard triclinic needle-like form that appears to have a perfectly round cross-section- each crystal basically looks like a dark, thick needle. They have the standard dark gray color and dull metallic luster of their species and are accompanied by bits of another sulfide mineral that has a rather dull golden color and a dull metallic luster- it might be pyrite or one of its close relatives. There is a small, dirty crust of crystalline quartz at one end of the piece, but no actual host rock is present.
cyl-1 ($100.00)
Poopo, Bolivia
CYLINDRITE specimen cyl-2
$ 30.00
$ 30.00
Dims: 1.5 x 0.5 x 0.3" (3.8 x 1.3 x 0.8 cm)
Wt: 6.8 g
Poopo, Bolivia
This small thumbnail specimen is made up almost entirely of intersecting Cylindrite crystals. These crystals are in moderately good condition, as much damage is evident, and reach lengths of up to 1.3" (3.3 cm) or more. All have the standard trigonal prismatic form that features the round, tapering cylindrical shape that is a hallmark of this mineral, and the dark silvery-gray color and dull metallic luster that are often standar for metallic sulfides. There is no host rock present.
cyl-2 ($ 30.00)
Poopo, Bolivia
CYLINDRITE specimen cyl-3
$ 120.00
$ 120.00
Dims: 4.9 x 2.3 x 1.9" (12.4 x 5.8 x 4.8 cm)
Wt: 14.7 oz. (417 g)
near Llallagua, Potosi Department, Bolivia
A large spray of Cylindrite spikes permeates the gray metallic host rock of this cabinet specimen. It is likely that many of these crystals exceed 2" (5 cm) in length, and though many of the exposed crystals are damaged or incomplete, those that extend into the host are in good condition. The crystals have the classic cylindrical shape that is the hallmark and namesake of the specie, and all have a dark silvery-gray color and a dull metallic luster- each strongly resembles the lead of a pencil. I cannot define the host rock, but it appears to contain a substantial amount of calcite.
cyl-3 ($120.00)
near Llallagua, Potosi Department, Bolivia
CYLINDRITE specimen cyl-4
$ 90.00
$ 90.00
Dims: 2.6 x 1.6 x 1.0" (6.6 x 4.2 x 2.6 cm)
Wt: 4.3 oz. (121 g)
near Llallagua, Potosi Department, Bolivia
This hand specimen consists of many heavily intergrown Cylindrite sprays. Each of these sprays is made up of dozens of tightly packed Cylindrite crystals, most of which are broken or damaged to some degree, that reach lengths of 1.3" (3.3 cm). These crystals have good form and the classic long, thin cylindrical shape whence comes their name. Their color is a moderately dark silvery-gray and their luster is metallic and rather dull. A small amount of a nondescript, dull-gray host rock is present.
cyl-4 ($ 90.00)
near Llallagua, Potosi Department, Bolivia
CYLINDRITE specimen cyl-5
$ 60.00
$ 60.00
Dims: 2.3 x 1.8 x 1.1" (5.9 x 4.5 x 2.7 cm)
Wt: 3.4 oz. (96 g)
near Llallagua, Potosi Department, Bolivia
Several Cylindrite sprays are embedded in the metallic host rock of this hand specimen. Each spray is made up of many radiating Cylindrite crystals, some of which are damaged or broken due to their exposure- they reach lengths of just over 1" (2.5 cm). All have excellent cylindrical shape (hence their name) and the standard dark silvery-gray color and dull metallic luster. I cannot define the host rock, but it is definitely metallic in nature.
cyl-5 ($ 60.00)
near Llallagua, Potosi Department, Bolivia
CYLINDRITE specimen cyl-7
$ 30.00
$ 30.00
Dims: 2.0 x 0.9 x 0.7" (5.0 x 2.4 x 1.7 cm)
Wt: 24 g
near Llallagua, Potosi Department, Bolivia
Scores of Cylindrite crystals are partly intergrown to form this hand specimen. The crystals are in fair condition at best, as most of them are broken and incomplete, and do not tend to exceed 1" (2.5 cm) in length. All have the tapering, cylindrical form that is classic for this mineral, along with the standard dark gray color and dull metallic luster. There does not appear to be any other material present.
cyl-7 ($ 30.00)
near Llallagua, Potosi Department, Bolivia
CYLINDRITE specimen cyl-6
$ 40.00
$ 40.00
Dims: 1.4 x 1.4 x 1.0" (3.6 x 3.5 x 2.5 cm)
Wt: 1.9 oz. (55 g)
near Llallagua, Potosi Department, Bolivia
This lovely hand specimen is made up almost entirely of intergrown Cylindrite needles. These needles reach nearly 1.5" (3.8 cm) in length and are generally in good condition - though many are noticeably damaged, several have complete terminations, including one particularly exposed crystal. All have a thin, cylindrical habit and are considered trigonal in form. Their gray color and dull metallic luster are standard for the specie, and all are, of course, opaque.
cyl-6 ($ 40.00)
near Llallagua, Potosi Department, Bolivia
CYLINDRITE specimen cyl-8
$ 55.00
$ 55.00
Dims: 2.8x1.4x2.0" (7.1x3.5x5.1 cm)
Wt: 5.7 oz. (162g)
Colquechaca, Potosi, Bolivia
This hand specimen is mostly cylindrite by weight, and features some cylinders that are up to 3mm in diameter. Also, some of the crystals reveal their true form, as rolled up sheets of the mineral that only appear cylindrical. The remainder of the specimen is a nearly massive reddish-brown mineral, likely cassiterite.
cyl-8 ($ 55.00)
Colquechaca, Potosi, Bolivia
CYLINDRITE specimen cyl-9
$ 65.00
$ 65.00
Dims: 2.8x2.2x2.2" (7.0x5.6x5.6cm)
Wt: 12.2 oz. (344g)
Colquechaca, Potosi, Bolivia
This cylindrite specimen has some of the largest (diameter) cylindrite crystals I have ever seen. Many specimens have much longer crystals, but I don't remember any as "fat" as these. A number of the crystals exceed 2mm in diameter, with one approaching 3mm. There are many somewhat radial clusters of crystals, although for the most part, the specimen is composed of masses of intergrown cylinders. There are other minerals present, notably including many small transparent quartz crystals, patches of what appears to be sphalerite, and some interesting black "roses" which may be hematite.
cyl-9 ($ 65.00)
Colquechaca, Potosi, Bolivia