Mineral Information and Data:

ZnS [CNMNC approved formula]

Named after the French chemist, Charles A. Wurtze (1817-1884).

IMA status : Valid species (Pre-IMA 1861) Grandfathered
(8th edition) :  
  (02) Sulfides - Including Selenides and Tellurides
  (02.08) where Am Bn Xp, with (m+n):p=1:1
  (02.08.07) Wurtzite Group (Hexagonal: P63mc)
(10th edition) :
  (02) Sulfides
  (02.C) Metal Sulfides, M:S = 1:1 (and similar)
  (02.CB) With Zn, Fe, Cu, Ag, etc.
Crystal system: Hexagonal System
Point group (H-M): 6mm — dihexagonal-pyramidal
Space group: P63mc
Unit cell: a = 3.82Å, c = 6.26Å, Z=2
Crystal Habit: Crystals to 1.5 cm, commonly hemimorphic pyramidal {5052} and {1011}; also short prismatic to tabular {0001}; typically striated horizontally on {1010} and {1011}. The polytypes show steepening of the pyramid as the repeat distance increases along {0001}. As concentrically banded crusts, fibrous or columnar.
Color: Deep reddish brown to dark brown to brown-black; yellow to dark brown internal reflections common in reflected light
Diaphaneity: Translucent
Luster: Resinous, brilliant submetallic on crystal faces
Hardness (Mohs): 3.5 - 4
Measured Density: 4.09 g/cm3
Cleavage: Easy on {1120}; difficult on {0001}
Tenacity: Brittle
Streak: Brown
Polymorphism and Series: Trimorphous with matraite and sphalerite.
Polytypes 2H, 4H, 6H, 8H, 10H, 15R, 18R, and 21R are known.
Geologic Setting: Of hydrothermal origin in veins with other sulfides. Also along shrinkage fractures in clay-ironstone concretions, of low-temperature origin.
Mineral Association: Sphalerite, pyrite, chalcopyrite, barite, marcasite
Other Properties: Gemstone Unlikely Available. BioMineral.


Hemimorphic pyramidal crystals, much like stacked cones which are striated horizontally to 1 mm, each is a translucent yellow to orange brown or even bronzy - iridescent.
Origin: Agios Philippos Pb-Zn deposit, Kirka, Xánthi Prefecture, Thrace Dept., Greece.
Sample size: 3 x 2 x 2 cm
Photo: Tom Loomis


(zoom-in of above)


Origin: Siglo XX Mine, Llallagua, Bolivia
Sample size: 3 x 2 x 1.75 cm
Photo: Rob Lavinsky


(zoom-in of above)