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  

Rare Minerals

Tuesday, 23 April 2024 06:00 PM

Introducing the "Rare Minerals" gallery which is part of our New Additions galleries. This gallery contains mineral specimens for sale including arsenopyrite, camaronesite, gormanite, gugiaite, koutekite, and ranunculite and more from places like Panasqueira, Covilha, Amazonas, Brazil, Cuya NE9, Cuya, Camarones Valley, Arica Prov., Chile, Big Fish River, Dawson dist., Yukon Territory, Canada, Dugdu alkaline complex, Tuva, Siberia, Russia, Mohawk mine, Keweenaw Co., Michigan, United States, and Kobokobo Pegmatite, Sud-Kivu, Democratic Republic of Congo.

Arsenopyrite

with Pyrite - #BAC64023
Locality
Panasqueira, Covilha, Amazonas, Brazil 
Formula
FeAsS 
Availability
Available
Price
$25.00
Size
4.5 x 2 x 2.5 cm - Miniature 
Tagged
sulfide  

Bladed crystals of Arsenopyrite to 2cm long with a second generation of cockscomb habit Arsenopyrite. There are also numberous micro, cubic crystals of Pyrite.  It is quite interesting.


Arsenopyrite

Formula
FeAsS 
Crystal System
Monoclinic 
Crystal Habit
Striated, Euhedral Crystals, Prismatic 
Cleavage
one distinct 
Luster
Metallic 
Color
tin white, light steel gray 
Streak
black 
Geological Setting
Widespread. Most commonly found in medium to high temperature veins.  
Class
Monoclinic - Prismatic 
Fracture
Brittle 
Hardness
5.5 to 6 
Collection
William & Anne Cook Collection

Camaronesite

#BW63991
Locality
Cuya NE9, Cuya, Camarones Valley, Arica Prov., Chile 
Formula
[Fe3+(H2O)2(PO3OH)]2(SO4)1-2H2
Availability
Sold
Size
2.8 x 2 x 2 cm - Thumbnail 
Tagged
phosphate  
Special Info
Type Locality 

Purple sugary crystalline masses.


Camaronesite

Collection
Bill Wilson Collection
Special Info
Type Locality

Gormanite

#BAC64021
Locality
Big Fish River, Dawson dist., Yukon Territory, Canada 
Formula
Fe2+3Al4(PO4)4(OH)6·2H2
Availability
Sold
Size
6 x 2 x 2.3 cm - Sm Cabinet 
Tagged
phosphate  
Special Info
Type Locality 

Dark green to dark blue divergent groups of compact fibrous crystals to 8mm.


Gormanite

Formula
Fe2+3Al4(PO4)4(OH)6·2H2
Crystal System
Triclinic 
Crystal Habit
Radial, Aggregates, Bladed 
Cleavage
Indistinct, None, None 
Luster
Vitreous (Glassy) 
Color
blue green 
Streak
pale green 
Class
Triclinic 
Hardness
4-5 
Collection
William & Anne Cook Collection
Special Info
Type Locality
Mineralpedia
View Gormanite
On Dakota Matrix
Previously Sold Gormanite
On Dakota Matrix
Other Available Gormanite
WebMineral
View Gormanite
Mindat
View Gormanite

Gugiaite

#63676
Locality
Dugdu alkaline complex, Tuva, Siberia, Russia 
Formula
Ca2BeSi2O7 
Availability
Available
Price
$75.00
Size
0.3 x 0.2 x 0.2 cm - Thumbnail 
Tagged
beryllium  
Special Info
Type Locality 
Special Info
XRD Confirmed 

Light yellow plates of Gugiaite with dark purple Fluorite. Gugiaite is a rather rare beryllium silicate found in only five to six places in the world.


Gugiaite

Formula
Ca2BeSi2O7 
Crystal System
Tetragonal 
Cleavage
Perfect, Distinct, Indistinct 
Luster
Vitreous (Glassy) 
Color
colorless 
Streak
white 
Class
Tetragonal - Scalenohedral 
Fracture
Uneven 
Hardness
3-4 
Special Info
Type Locality
Special Info
XRD Confirmed
On Dakota Matrix
Previously Sold Gugiaite
On Dakota Matrix
Other Available Gugiaite
WebMineral
View Gugiaite
Mindat
View Gugiaite

Koutekite

with Paxite - #64010
Locality
Mohawk mine, Keweenaw Co., Michigan, United States 
Formula
Cu5As2 
Availability
Available
Price
$125.00
Size
1.6 x 1.2 x 0.9 cm - Thumbnail 
Tagged
sulfide , copper  

The Paxite stands out readily on this specimen as bright silvery crystal grains. Admittedly, I am not sure what the Koutekite is on this specimen. Norman King has a good photo on Mindat of the Paxite. It is likely an inclusion. There is also a tarnished metallic mineral.


Koutekite

Formula
Cu5As2 
Crystal System
Hexagonal 
Crystal Habit
Microscopic Crystals 
Luster
Metallic 
Color
gray blue 
Streak
black 
Class
Hexagonal - Dihexagonal Dipyramidal 
Hardness
3.5 
Collection
William & Anne Cook Collection
SOLD
Ranunculite - BAC61873
Ranunculite - BAC61873

Ranunculite

#BAC61873
Locality
Kobokobo Pegmatite, Sud-Kivu, Democratic Republic of Congo 
Formula
Al(UO2)(PO3OH)(OH)3·4H2
Availability
Sold
Size
0.8 x 0.5 x 0.4 cm - Thumbnail 
Special Info
Radioactive!! 
Special Info
Type Locality 

Yellow earthy mass.


Ranunculite

Formula
Al(UO2)(PO3OH)(OH)3·4H2
Crystal System
Monoclinic 
Crystal Habit
Nodular, Platy, Botryoidal 
Cleavage
Perfect, Perfect, None 
Color
golden yellow, canary yellow 
Streak
light yellow 
Class
Monoclinic 
Fracture
Irregular 
Hardness
Collection
William & Anne Cook Collection
Special Info
Radioactive!!
Special Info
Type Locality

All photos by Dakota Matrix and are Copyrighted © and may not be used without permission. Copyright © 2024 - Dakota Matrix Minerals, Inc. Privacy | Terms & Conditions | Site Map