Cylindrite
Current inventory: 0 gems
 

  
Cylindrite is named from the Greek word κύλιυδροσ (kylindros), meaning a roll, in allusion to the typical cylindrical form of the crystals.

Discovered in 1893; IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

Pb₃Sn₄FeSb₂S₁₄

Lead Tin Iron Antimony Sufide

Molecular Weight:

1,844.71 gm

Composition:

Iron

3.03 %

Fe

Tin

25.74 %

Sn

Antimony

13.20 %

Sb

Lead

33.70 %

Pb

Sulfur

24.34 %

O

100.00 %

Classification

Mineral Classification:

Sulfides and Sulfosalts

Strunz 8th Ed. ID:

2/C.17-0

Nickel-Strunz 10th Ed. ID:

2.HF.25a

2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
H : Sulfosalts of SnS archetype
F : With SnS and PbS archetype structure units

Related to:

Cylindrite Group.

Members of Group:

Cylindrite Group: Abramovite, Cylindrite, Lévyclaudite

Varieties:

None

Synonyms:

Kylindrite

Crystal Data

Crystallography:

Triclinic - Pinacoidal

Crystal Habit:

In concentric spherical or tubular shells and aggregates, with individual cylindrical crystals up to 5 mm across and 2–3 cm in length, rarely terminated; also massive. 

Twinning:

None

Physical Properties

Cleavage:

Perfect on {100}

Fracture:

Malleable; deforms rather than breaking apart

Tenacity:

Malleable

Moh's Hardness:

2.5; Vickers: VHN₁₀₀=54 - 93 kg/mm²

Density:

5.43 - 5.49 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Optical Properties

Color:

Lead gray, grayish black. In reflected light, galena-white

Transparency:

Opaque

Luster:

Metallic

Refractive Index:

R1–R2: (400) 34.5–40.3, (420) 34.3–40.1, (440) 34.1–40.1, (460) 33.6–39.8, (480) 33.1–39.4, (500) 32.5–38.9, (520) 31.8–38.3, (540) 31.2–37.8, (560) 30.7–37.2, (580) 30.3–36.7, (600) 29.9–36.3, (620) 29.6–35.9, (640) 29.3–35.5, (660) 28.9–35.1, (680) 28.6–34.7, (700) 28.4–34.4

Birefringence:

0.000 (opaque)

Dispersion:

n/a

Pleochroism:

Extremely weak: parallel to elongation gray-white, perpendicular to the elongation, darker gray-white. Stronger in oil.

Anisotropism:

Distinct; gray to pale yellowish or brownish gray

Occurances

Geological Setting:

In tin-bearing hydrothermal veins.

Common Associations:

Franckeite, Stannite, Incaite, Potosiite, Teallite, Jamesonite, Boulangerite, Cassiterite, Galena, Pyrite, Sphalerite

Common Impurities:

Ag

Type Locality:

Santa Cruz Mine, Poopó town, Poopó Province, Oruro Department, Bolivia

Year Discovered:

1893

View mineral photos:

Cylindrite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Cylindrite is a very unusual sulfide mineral containing lead (Pb), tin (Sn), iron (Fe) and antimony (Sb). It has one of the most unique crystal habits of the mineral world. As its name implies, Cylindrite's crystals form as cylinders, or more acurately, as thin sheets rolled into tubes or cylinders. There are a couple other minerals whose crystals are formed like this, but they are microscopic tubes. Cylindrite's cylindrical crystals are easily seen with the naked eye at up to 2-3 cm in length. Faceted gems are very rare and certainly a gem for collectors of the very unusual but mineral specimens are much more attractive and interesting with their often radiating cylindrical crystals. Faceted gems are lead gray to grayish black with a metallic luster and a Moh's hardness of only 2.5.

Cylindrite is named from the Greek word κύλιυδροσ (kylindros), meaning a roll, in allusion to the typical cylindrical form of the crystals.

Cylindrite distribution: Bolivia, with fine examples from Poopó, in the Santa Cruz (Type Locality) and Trinacria mines; at the Porvenir and Maria Francisca mines, Huanuni; from the Nueva Virginia vein, Colquechaca; and from the Purisima vein, all in Oruro; also from Llallagua, Potosí. In the Smirnovsk deposit, Transbaikalia, Russia.
 

  
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