mineral specimens
rare minerals
mineral dealer
systematic minerals
Black Hills minerals
fine minerals
mineral dealer
Dana minerals
IMA minerals
mineral collections
rock and minerals
gem crystal
0 item @ $0.00  

Ore Minerals 5

Tuesday, 31 January 2017 09:00 AM

A favorite subject amongst geologists/mineral collectors, the Ore Minerals SE will have several ore examples from some of the most famous mines in the world. Take a look at Ore Minerals  4 for a taste of what Ore Minerals 5 will be like.

Acanthite

with silfides - #46308
Locality
Greens Creek, Admiralty dist., Juneau Borough, Alaska 
Formula
Ag2
Availability
Sold
Size
10 x 6 x 5 cm - Cabinet 
Tagged
sulfide , silver  

1 lb 10 oz one side is mostly Acanthite the remaining is mixed sulfides. Acanthite is one of the most important epithermal minerals of silver. Acanthite was a major ore component at the Comstock Lode in Nevada, also in Creede, Colorado and Fresnillo, Mexico. 

The Greens Creek mine is one the largest producing primary silver mines in the world. The massive sulfide deposit was discovered in 1973 and began operations in 1989. In 2015 it produced 8.3 million ounces of silver.


Acanthite

Formula
Ag2
Crystal System
Monoclinic 
Crystal Habit
Blocky, Skeletal, Arborescent 
Cleavage
poor to none 
Luster
Metallic 
Color
lead gray, gray, iron black 
Streak
shining black 
Class
Monoclinic - Prismatic 
Fracture
Sectile 
Hardness
2-2.5 
Collection
Chris van Laer Collection
Mineralpedia
View Acanthite
On Dakota Matrix
Previously Sold Acanthite
On Dakota Matrix
Other Available Acanthite
WebMineral
View Acanthite
Mindat
View Acanthite

Bornite

with Chalcocite, Pyrite, Chalcopyrite - #45836
Locality
Butte dist., Silver Bow Co., Montana, United States 
Formula
Cu5FeS4 
Availability
Sold
Size
8 x 6.5 x 6 cm - Sm Cabinet 
Tagged
sulfide , copper  

A beautiful specimen of almost pure bluish, homogenous and fine grained mass with dark grey Chalcocite and a band of 1-4mm crystals of pyrite and chalcopyrite. Cut smooth on one side to show mineralization. 1 lb 8 oz.

Bornite generally contains about 63% copper and is an important ore of copper. It is a supergene enrichment product of  chalcopyrite. Bornite was a significant ore at Butte.


Bornite

Formula
Cu5FeS4 
Crystal System
Orthorhombic 
Crystal Habit
Massive - Granular, Reniform, Granular 
Cleavage
Imperfect, None, None 
Luster
Metallic 
Color
copper red, bronze brown, purple 
Streak
grayish black 
Class
Orthorhombic - Dipyramidal 
Fracture
Conchoidal 
Hardness
Collection
Chris van Laer Collection
Mineralpedia
View Bornite
On Dakota Matrix
Previously Sold Bornite
On Dakota Matrix
Other Available Bornite
WebMineral
View Bornite
Mindat
View Bornite

Bornite

#45901
Locality
Magma mine, Pinal Co., Arizona, United States 
Formula
Cu5FeS4 
Availability
Sold
Size
8 x 5 x 4.5 cm - Sm Cabinet 
Tagged
sulfide , copper  

A crystalline mass of blue iridescent Bornite weighing 9 oz.


Bornite

Formula
Cu5FeS4 
Crystal System
Orthorhombic 
Crystal Habit
Massive - Granular, Reniform, Granular 
Cleavage
Imperfect, None, None 
Luster
Metallic 
Color
copper red, bronze brown, purple 
Streak
grayish black 
Class
Orthorhombic - Dipyramidal 
Fracture
Conchoidal 
Hardness
Collection
Chris van Laer Collection
Mineralpedia
View Bornite
On Dakota Matrix
Previously Sold Bornite
On Dakota Matrix
Other Available Bornite
WebMineral
View Bornite
Mindat
View Bornite

Chalcopyrite

#45890
Locality
Blackbird mine, Lemhi Co., Idaho, United States 
Formula
Cu1+Fe3+S2 
Availability
Sold
Size
7 x 6 x 6 cm - Sm Cabinet 
Tagged
sulfide , copper  

13 oz of mixed sulfide, coarsely crystalline with other sulfides.

The Blackbird mine is now a EPA superfund site, having history dating to the late 1800's. Since then, copper, nickel and cobalt has been extracted from the ores. Acid-rock drainage now hunts the area. The Blackbird mine produced copper-cobalt ore since the early 1900's. Ore geology was generally characterized as strata-bound deposits in the Proterozoic Yellowjacket Formation with probable epigenetic hydrothermal veining proximal to the mined deposit. The Blackbird was known for gorgeous Vivianite and Ludlamite specimens. 


Chalcopyrite

Formula
Cu1+Fe3+S2 
Crystal System
Tetragonal 
Crystal Habit
Euhedral Crystals, Striated, Druse 
Cleavage
Indistinct, None, None 
Luster
Metallic 
Color
brass yellow, honey yellow 
Streak
greenish black 
Class
Tetragonal - Scalenohedral 
Fracture
Brittle 
Hardness
3.5 
Collection
Chris van Laer Collection

Chalcopyrite

#45902
Locality
Cable mine, Anaconda, Montana, United States 
Formula
Cu1+Fe3+S2 
Availability
Sold
Size
6.5 x 6 x 2.5 cm - Sm Cabinet 
Tagged
copper , sulfides  

Solid, fine crystalline mass of nearly all Chalcopyrite with other sulfides.

Chalcopyrite is the most widespread mineral of copper. It contains 34% copper and thus an important ore of copper. 


Chalcopyrite

Formula
Cu1+Fe3+S2 
Crystal System
Tetragonal 
Crystal Habit
Euhedral Crystals, Striated, Druse 
Cleavage
Indistinct, None, None 
Luster
Metallic 
Color
brass yellow, honey yellow 
Streak
greenish black 
Class
Tetragonal - Scalenohedral 
Fracture
Brittle 
Hardness
3.5 
Collection
Chris van Laer Collection

Chromite

#45883
Locality
Stillwater mine, Nye Co., Montana, United States 
Formula
Fe2+Cr2O4 
Availability
Sold
Size
11 x 7 x 6 cm - Cabinet 

Rich, solid granular or crystalline aggregate of black Chromite ore. Though not producing Chromite ore, this large 30 mile complex of layer igneus mafic rock currently does not produce chromium ore. It is currently mined for its platinum and palladium only. Ore specimens are hard to obtain.

Widely used in chemicals, metals and refractory materials. Used to harden iron, nonferrous alloys and steel. The addition of 10% chromium also creates corrosion and oxidation resistant alloys such as stainless steel. According to the USGS Minerals Commodity Summary of 2106, about 95% of the world’s chromium resources is geographically concentrated in Kazakhstan and southern Africa; U.S. chromium resources are mostly in the Stillwater Complex in Montana although not currently producing chromium. 

1 lb 5oz


Chromite

Formula
Fe2+Cr2O4 
Crystal System
Isometric 
Crystal Habit
Massive - Granular, Granular, Nuggets 
Cleavage
None, None, None 
Luster
Metallic 
Color
black, brownish black 
Streak
brown 
Class
Isometric - Hexoctahedral 
Fracture
Uneven 
Hardness
5.5 
Collection
Chris van Laer Collection
Mineralpedia
View Chromite
On Dakota Matrix
Previously Sold Chromite
On Dakota Matrix
Other Available Chromite
WebMineral
View Chromite
Mindat
View Chromite

All photos by Dakota Matrix and are Copyrighted © and may not be used without permission. Copyright © 2025 - Dakota Matrix Minerals, Inc. Privacy | Terms & Conditions | Site Map