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RARE MINERALS FOR DISCRIMINATING COLLECTORS

  
 


 

CLINOCLASE
Copper Stope, Majuba Hill Mine, Pershing County, Arizona
The best references to the finds of Clinoclase from the Copper Stope at Majuba Hill are in the following back issues of the “Mineralogical Record” magazine:
January-February 1985 (Nevada issue) -- article covering Majuba Hill on Pages 57-72, Clinoclase described on P. 64-65.
May-June 1993 – article covering Majuba Hill on Pages 171-180, Clinoclase described on Page 177.
The specimens featured here were collected in the Copper Stope by Martin Jensen in 1992-1993, circa the coordinates 1760N, 370W, about 55 feet above the level.  Jensen is the author of both of the articles referenced above.  The crystals on all specimens are dark blue-green, either as rich intergrowths of prismatic crystals, or as intergrowths of slightly curved rhombohedrons (Clinoclase is actually monoclinic). Chemical composition is:  Cu32+(AsO4)(OH)3

The two “Mineralogical Record” references are available for purchase, as follows:
Jan-Feb 1985, Vol. 16, No. 1 (Nevada issue)   $12.00                                   May-June 1993, Vol.  24, No. 3    $12.00

 

 

MI-

SPECIMEN SIZE
(INCHES)

SPECIMEN
PRICE

 

1635

7/8

5/8

5/8

SOLD

 

1636

1 1/4

1 1/8

1/4

$  18.00

 

1637

1 5/8

1 1/8

7/8

$  20.00

 

1638

1 3/8

1 3/8

1

$  18.00

 

1639

1 3/4

1 3/8

5/8

$  28.50

 

1640

1 7/8

1 3/8

1 1/8

$  35.00

 

1641

1 7/8

1 1/2

5/8

$  35.00

 

1642

2

1 5/8

1

$  38.50

 

1643

2 1/2

2

3/8

$  55.00

 


MI-1635
MI-1636
MI-1637
MI-1638
MI-1639

MI-1640
MI-1641
MI-1642
MI-1633		  

 

COWLESITE
Burnt Cabin Creek, Spray, Wheeler County, Oregon
The Burnt Cabin Creek occurrence of Cowlesite has provided some of the best quality specimens found at any of the Oregon occurrences.  Vugs completely lined with translucent white micro spheroids of Cowlesite are present on each of the specimens listed below.  Close-up photos of the vugs are shown here.  The vugs are in/on dark charcoal gray color basalt matrix. All items, except E., have sawed bases.  Additional information can be found in “Zeolites of the World”, Rudy Tschernich, P. 126-127 (1992).  All specimens were collected and prepared by R. Tschernich.

MI-1298

VUG SIZE
(MILLIMETERS)

SPECIMEN SIZE
(INCHES)

SPECIMEN
PRICE

A.

8 X 6

1 3/8

1 1/8

3/8

$14.00

B.

9 X 8

1 1/2

1 1/8

1/2

SOLD

C.

6 X 6 & 4 X 4

1 1/8

1 1/8

1/4

SOLD

D.

12 X 6

1 1/4

3/4

1/4+

$22.50

E.

15 X 12

1 1/4

1 1/4

1

SOLD

F.

15X 14

1 3/8

1 3/8

3/8

SOLD


A.


B.


C.


D.


E.


F.

All photos taken with the Dino-Lite Digital Microscope

 


TERLINGUACREEKITE
Perry Pit, Mariposa Mine, Terlingua Mining District, Brewster County, Texas (type locale)
Researchers have been working on characterizing this new Hg-bearing mineral since the late 1980’s, first found in very small amounts at the McDermitt Mine in Humboldt Co., Nevada.   About 5 years ago an orange to yellow-orange, crystallized, unknown mineral was encountered in the lower level of the Perry Pit at Terlingua.  It was determined to be identical to the massive unknown mineral that had previously been found in Nevada.  The general appearance of the Terlinguacreekite is as mm-sized crusts of variable thickness, on Calcite crystal sections.  Most Terlinguacreekite crusts are thin and almost cryptocrystalline, with no discernable crystal form.  Crystals are rare, and are up to 0.2 mm in length, subhedral and somewhat elongate with a maximum length:width ratio of 4:1.  Crystal system is orthorhombic.  Color is dark orange to reddish-orange, to yellow-orange with a yellow streak, vitreous luster, no obvious cleavage, and no fluorescence.  Terlinguacreekite is a mercury oxychloride with the chemical composition: Hg2+3O2Cl2.  In the table below, the following abbreviations apply to the habit of the Terlinguacreekite present on each of the specimens:  MX = micro crystals, XN = crystalline, BO = botryoidal, and MA = massive.  Specimens are priced according to the richness of the Terlinguacreekite, not relative to the size of the Calcite matrix.  Magnification of 20-30X is required for best appreciation of the crystallization.  All specimens are co-type.  IMA approved # 2004-018.

 

MI-1171

SPECIMEN SIZE
(INCHES)

HABIT

SPECIMEN
PRICE

A.

7/8

3/4

5/8

XN, BO

$   25.00

B.

5/8

1/2

1/2

MX, XN, MA

SOLD

C.

3/4

5/8

1/2

MX, XN, MA

SOLD

D.

5/8

1/2

1/2

MX, XN, BO

SOLD

E.

5/8

5/8

1/4

MX, XN, BO, MA

SOLD

F.

1 1/2

5/8

5/8

MX, XN, BO, MA

SOLD

G.

1 1/4

7/8

5/8

MX, XN, BO, MA

SOLD

H.

1 3/8

1

1/2

MX, XN, MA

SOLD

I.

1 1/8

3/4

1/2

MX, XN, BO, MA

SOLD

J.

5/8

5/8

1/2

MX, XN, BO, MA

SOLD

K.

1 1/2

1 1/4

1 1/8

MX, XN, BO, MA

$   85.00

L.

1 1/2

1 1/4

1 1/8

MX, XN, BO, MA

SOLD

M.

2 1/4

1 1/4

5/8

MX, XN, BO, MA

SOLD

N.

2

1 1/2

1

MX, XN, BO, MA

SOLD

O.

2

1 3/8

1/2

MX, XN, BO, MA

SOLD

P.

1

3/4

1/2

MX, XN, BO, MA

SOLD

Q.

2 1/4

1 1/2

3/4

MX, XN, BO, MA

SOLD

R.

1 1/2

3/4

1/4 to 1/2

MX, XN, BO, MA

SOLD

Photomicrographs of Terlinguacreekite crystals


 

 

A.
B.		 \
C.
D.
E.

F.
G.
H.
I.
J.

K.
L.
M.
N.
O.

P.
Q.
R.		    

 

 

COPPER, TENNANTITE
Tsumeb Mine, Tsumeb, Namibia
Two of the specimens pictured at the left are pairs, each cut from a single specimen of very high-grade ore containing masses and stringers of native Copper, with each half of the specimen polished on one surface.  Item MI-1423 is a single specimen, polished on two surfaces.  Associates noted include Tennantite, Cuprite, Mimetite (white), Goethite, Dolomite, Plancheite  Tsumcorite, Quartz, and Duftite though all associates are not present of every specimen.  These specimens would make excellent additions to any reference collection of Tsumeb minerals, with so many minerals identified in this unusual assemblage.  These specimens were obtained from Walter Kahn in the late 1970’s, and Kahn’s collection # 1263 is attached to specimen MI-1424.  Each half of the MI-1424 specimen has a thick band of metallic black Tennantite running diagonally across the wide end of the specimen.  Kahn was a German mineral collector for whom the mineral Warikahnite was named, described from Tsumeb in 1980.  The gram weight of each specimen is given below, simply as a size measurement.  The specimens are not sold by the gram.
 

ITEM
NUMBER
MI-

WEIGHT(GRAMS)

SPECIMEN SIZE
(INCHES)

SPECIMEN
PRICE

1422

5.60

3/4

1/2

3/8

$18.50

/ pair

9.88

3/4

3/8

3/8

1423

91.30

1 3/8

1 1/8

1

$ 20.00

1424

33.88

2

1

1/2

$48.50

/ pair

82.25

2 3/8

1 3/8

7/8
  
MI-1422
MI-1423
MI-1424

 

TELLURIUM (native)
San Miguel Mine, Moctezuma District, Sonora, Mexico
Metallic silver-gray massive native Tellurium is in light colored matrix.  Pricing is according to the richness of the native Tellurium, as well as relative to the amount of associated minerals present.  Matrix is massive Quartz / Barite.  Associates on items G. and H. include various amounts of one or more of the following:  Paratellurite, Tellurite, Buckhardtite, all in massive form.
 

 

MI-1227

SPECIMEN SIZE
(INCHES)

SPECIMEN
PRICE

A.

3/4

5/8

3/8

$ 16.00

B.

1 1/2

1

3/4

$ 18.50

C.

1 7/8

1 1/2

3/4

$ 28.50

D.

5/8

1/2

3/8

SOLD

E.

1 1/4

7/8

3/4

SOLD

F.

1

1

1/2

SOLD

G.

2 3/4

1 3/4

1 1/2

SOLD

H.

2 1/2

2

1 1/2

SOLD

 
A.
B.
C.
D.

E.
F.
G.
G.


 

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