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Ore Minerals 2

Friday, 06 January 2012 02:00 PM

Ore Minerals from historic mining camps. Learn more about Special Editions. View Upcoming Special Editions. To get NOTIFIED click here to get the exclusive DAKOTA MATRIX NOTIFIER.

Enargite

Brochantite - #30658
Locality
Burrus mine, Washoe Co., Nevada, United States 
Formula
Cu3AsS4 
Availability
Sold
Size
13 x 13 x 6 cm - Cabinet 
Tagged
Ore Minerals  

Just a large impressive chunk of coarsely crystalline Enargite.


Enargite

Formula
Cu3AsS4 
Crystal System
Orthorhombic 
Crystal Habit
Euhedral Crystals, Massive - Granular, Prismatic 
Cleavage
Perfect, Distinct, Distinct 
Luster
Metallic 
Color
steel gray, blackish gray, violet black 
Streak
black 
Class
Orthorhombic - Pyramidal 
Fracture
Uneven 
Hardness
Collection
Phillips Collection
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Franklinite

Willemite - #PD30626
Locality
Franklin, Sussex Co., New Jersey, United States 
Formula
ZnFe3+2O4 
Availability
Sold
Size
11 x 5 x 6.5 cm - Cabinet 
Tagged
Ore Minerals  

This is a really fine big Franklin Ore specimen with huge black octahedral Franklinite crystals to 3cm on course crystalline Franklinite and Willemite matrix. Of course all the Willemite fluoresces bright green under UV light, see pop-up photo. Also, a label from the University of Chicago - Dept of Geological Sciences accompanies this specimen with the number 1093 that corresponds to a number on the side of the specimen. The specimen most likely originated from Paul Moore.
According to the Bateman's classic work "Economic Mineral Deposits" - Second Edition (1950), which although it is over 60 years old still has great relevant information on deposits, the Franklin-Sterling Hill Zinc District has been mined since 1840 and is unique with no known counterpart in the world.


Franklinite

Formula
ZnFe3+2O4 
Crystal System
Isometric 
Crystal Habit
Euhedral Crystals, Massive, Crystalline - Fine 
Cleavage
None, None, None 
Luster
Sub Metallic 
Color
black, brownish black 
Streak
reddish brown 
Class
Isometric - Hexoctahedral 
Fracture
Uneven 
Hardness
5.5-6 
Collection
Phillips Collection

Galena

Arsenopyrite and Chalcopyrite - #PD30647
Locality
Silverfields mine, Cobalt dist., Ontario, Canada 
Formula
PbS 
Availability
Sold
Size
9.5 x 8 x 1 cm - Cabinet 
Tagged
Ore Minerals  

Excellent slab of Galena with Arsenopyrite and Chalcopyrite mostly likely from Petruk's group 5 mineralization, the Fe-As assemblage. This assemblage is characterized be a high content of Arsenopyrite. Cobalt was a world class Silver deposit which was discovered by a blacksmith in 1903. The pop-up photos show some unique and unusual ore textures.


Galena

Formula
PbS 
Crystal System
Isometric 
Crystal Habit
Euhedral Crystals, Massive - Granular, Massive 
Cleavage
Perfect, Perfect, Perfect 
Luster
Metallic 
Color
light lead gray, dark lead gray 
Streak
grayish black 
Class
Isometric - Hexoctahedral 
Fracture
Brittle 
Hardness
2.5 
Collection
Phillips Collection
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Goethite - PD30427
Goethite - PD30427

Goethite

#PD30427
Locality
Restormel Iron mine, St. Austell district, Cornwall, England 
Formula
FeO(OH) 
Availability
Sold
Size
7 x 4 x 2.5 cm - Sm Cabinet 

Hardly good photos for this rather shiny Goethite specimen. The Goethite crystals occur as divergent groups to 7mm within drusy Quartz matrix. There are several groups of Goethite and one group shows the clasic zoned patterns on the backside.


Goethite

Formula
FeO(OH) 
Crystal System
Orthorhombic 
Crystal Habit
Acicular, Reniform, Radial 
Cleavage
Perfect, Distinct, None 
Luster
Adamantine - Silky 
Color
brown, reddish brown, yellowish brown, brownish yellow, ocher yellow 
Streak
yellowish brown 
Class
Orthorhombic - Dipyramidal 
Fracture
Hackly 
Hardness
5-5.5 
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Graphite

#30630
Locality
Bogala Mine, Sabaragamuwa Province, Sri Lanka 
Formula
Availability
Sold
Size
8 x 5 x 10 cm - Cabinet 
Tagged
Ore Minerals  

Piece of silvery-gray soft foliated Graphite.
According to the the USGS Mineral Yearbook 2010 Graphite production in Sri Lanka was 3,437 metric tons.


Graphite

Formula
Crystal System
Hexagonal 
Crystal Habit
Foliated, Tabular, Earthy 
Cleavage
Perfect, None, None 
Luster
Sub Metallic 
Color
iron black, dark gray, black, steel gray 
Streak
black 
Class
Hexagonal - Dihexagonal Dipyramidal 
Fracture
Sectile 
Hardness
1.5-2 
Collection
Phillips Collection
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Homestake Rock Suite

#MS010496
Locality
Homestake mine, Lawrence Co., South Dakota, United States 
Availability
Sold
Size
30 x 30 x 12 cm - Cabinet 
Tagged
Ore Minerals  

The Homestake deepest Gold Mine in North America and producted more than 40 million ounces of Gold. It is now the site for the National Science Foundation's Deep Underground Science and Engineering Laboratory where scientists from all over the world will research physics (neutrinos!), mining, rock mechanics, biology, geology, and more.
This is a deluxe Homestake Rock Suite with 14 rock samples from the different formations in the Homestake, Lead district including two samples of Homestake formation ore with one containing visible gold. Each rock sample is a good handsample size from 4-9cm and has a number that corresponds to a key on the inside of the handcrafted wood box. Additionally we will include a Homestake Stock Certificate (dated 1941) and a a Homestake Centennial booklet with lots of good information and pictures of Homestake in its boom mining days.
The approximate weight is 12-15 pounds and the size is 16.5 x 12.5 x 6 inches and will definitely require extra shipping expenses.
This suite was prepared by the Student Chapter of the Society of Economic Geologists at the South Dakota School of Mines & Technology here in Rapid City, SD.


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