 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|||||||||||||||||||||
 |
 |
 |
 |
 |
 |
 |
 |
 |
|
|||||||||||||
 |
 |
 |
 |
 |
 |
|
||||||||||||||||
 |
 |
 |
 |
|
||||||||||||||||||
 |
 |
 |
 |
|
||||||||||||||||||
 |
 |
 |
|
|||||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||||||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|||||||||||||
|
|
|
|
|
|
|
||||||||||||||||
|
|
|
|
|
||||||||||||||||||
|
|
|
|
|
||||||||||||||||||
|
|
|
|
|||||||||||||||||||
(Cu,Fe)12As4S13 Cubic
 |
|
|
 |
|
|
| Figure 21-38. Crystal drawing of tennantite from Sterling Hill. Drawing is from Palache (1935) who provided crystallographic data. | ||
|
Tennantite was first found at Sterling Hill by Lawson Bauer and confirmed by Palache (1928a, 1935). Reflected-light studies indicate it is commonly present as an accessory mineral in the late sulfide veins at Franklin and Sterling Hill.
Sterling Hill tennantite has been observed megascopically only on the material described by Palache (1928a). Here it occurs as 2-3 mm, equant crystals with {111}, {110} and {211} as the dominant forms, as illustrated by Palache (Figure 21-38).
This tennantite is deep red, appearing black upon casual observation, and has a metallic luster and no cleavage. It could be confused with some single-crystal hematite.
Tennantite is a copper iron arsenic sulfide mineral. Preliminary analysis of the original material yielded a composition of (Cu9.99Zn1.24Fe0.77) (As3.69Sb0.31)S13. Analysis of a specimen with loellingite, from a separate assemblage described below, yielded Cu 43.05, Zn 5.65, Fe 3.1, As 19.1, Sb 1.25, S 28.0, total = 100.15 wt. % (E. A. J. Burke, pers. comm.). This yields, on the basis of 12 (Cu,Fe,Zn), the composition (Cu9.92Zn1.27Fe0.81)(As3.73Sb0.15)S12.78, very close to the composition of the original material and demonstrating that both specimens have Zn > Fe.
The original find of tennantite was on the 900 level at Sterling Hill. Here it occurs in a vein, and coats an assemblage of actinolite, feldspar, titanite, and epidote, and is in turn coated with stilbite crystals.
Tennantite also was found intimately associated with bornite and loellingite on the 1300 level and with bornite, chalcopyrite, galena, and sphalerite on the 800 level. It was seen, but not studied, in a number of the sulfide veins, always sparse and associated with bornite and sphalerite.
Jenkins and Misiur (1994) reported it from below the 700 level, with an Sb:As ratio of 15:85, associated with chalcopyrite, galena, and other minerals.
|
|
|||
|
|
||||
|
||||
| Copyright © 1995 by Pete J. Dunn |
Website
by Herb Yeates
|
|||
|
|
|
|||
|
Link
to homepage
|
||||
|
This
page created: January 11, 2001 |
||||
|
|
|
|||
