Koritnigite


Composition: Zn(AsO3)(OH).H2O
Crystal System : Triclinic
Colours: Colourless
Lustre : Pearly
Hardness (H) : 2
Specific Gravity (S.G) : 3.54
Year of Discovery: 1978
IMA Number: 1978-008
IMA Status: Approved
Discovered By: Gunther Schnorrer (German mineralogist)
Named for: Sigmund Koritnig (German mineralogist)
References: Keller et al. (1979a)

Tsumeb is the Type Locality

Distribution

Extremely rare. The type specimen is from the second oxidation zone, on 31 Level. Also found in the third oxidation zone.

Occurrence

  • Supergene
  • 2nd Oxidation Zone
  • 3rd Oxidation Zone

Paragenetic and General Notes

The type assemblage comprises koritnigite in cavities in tennantite, with cuprian adamite, stranskiite, lavendulan, k├Âttigite, prosperite, and o'danielite, from the E.9 pillar, on 31 Level. 

Gebhard (1999) notes that koritnigite, visually resembling gypsum, was found, also on 31 Level, filling veins in chalcocite. 

In the third oxidation zone koritngite was found as "sugar-like, white crusts" on specimens with the as yet unnamed minerals "GS1" and "GS2" (Gebhard, op. cit.).

(Compositionally, the green, gel-like "GS2" resembles koritnigite but it yields no x-ray diffraction pattern. White crystalline inclusions in "GS2" x-ray as koritnigite, however, and when GS2 itself is heated to 300 degrees C, it also yields a koritnigite pattern (Bill Pinch, personal communiction, 2014). GS2 appears to be an amorphous equivalent of koritnigite, which adopts the koritnigite structure only at elevated temperatures.)